What this calculator works out
Most collection valuations start in the wrong place. You look up what individual items sell for, multiply by how many you own, and arrive at a number that feels like what the collection is worth. It almost never is.
Three things sit between that figure and the money in your hand. Condition, which moves value further than most owners expect. Completeness — a board game missing a component, a book without its dust jacket, a record without its inner sleeve is worth a fraction of the same item intact. And the route you sell through, which is by far the largest factor: the same collection can return four or five times more sold patiently as individual listings than it does handed to a bulk buyer in one go.
This calculator takes the catalogue value as a starting point and works forward through all three, ending at a realistic range for what you would actually receive after fees. It covers board games, vinyl, books, comics, video games, trading cards, discs and model kits, because the arithmetic is the same for all of them and only the terminology changes.
Your collection
Three different values, and why they never match
The single most common source of disappointment when selling a collection is not knowing which value is being quoted. There are three, and they can differ by a factor of ten for the same items.
| Value | What it means | Where you see it |
|---|---|---|
| Catalogue or guide value | What items have sold for at their best, in good condition, to the right buyer | Price guides, completed listings, collector databases |
| Realisable value | What you would receive, after condition, completeness, fees and the route you use | What this calculator estimates |
| Replacement value | What it would cost to buy the collection again, at retail, today | Insurance policies and schedules |
Replacement value is usually the highest of the three and realisable value the lowest, sometimes by a wide margin. An insurer quoting a replacement figure is not telling you what your collection would sell for, and a dealer quoting a trade price is not telling you it is worthless — they are answering different questions.
Insuring: replacement value, and your insurer will want evidence. Selling: realisable value, which is what this page estimates. Probate or division of an estate: usually open market value at the date of death, which is closer to realisable than to replacement, and for anything substantial should come from a qualified valuer rather than a calculator.
How this calculator works
Four steps, applied in the order the value actually gets lost.
Catalogue value = number of items × typical value of one item
Adjusted value = catalogue value × condition factor × completeness factor
Expected realisation = adjusted value × the range for your selling route
Net proceeds = expected realisation − fees and commissionCondition runs from 1.3 for sealed or as-new down to 0.3 for damaged. That spread is wider than most owners expect and it is not a penalty for scuffs — for most collectables the market is thin and buyers who want an item at all usually want a good one.
Completeness multiplies again, from 1.0 for complete with original packaging down to 0.4 for significantly incomplete. It is separate from condition because the two are independent: a pristine board game missing one meeple is in excellent condition and incomplete.
The selling route is applied as a range rather than a single figure, because it depends on patience, presentation and luck. A dealer buying outright has to fund stock, storage and the wait for a buyer, so 25–45% of private-sale value is a working offer rather than an insult.
Fees are entered separately and default to 13%, which is in the usual region for online marketplaces. Fee structures change regularly and differ by category, and some now charge the buyer rather than the seller. Check the current terms for wherever you are actually selling rather than relying on the default.
Collections are rarely uniform. A few valuable pieces among a mass of ordinary ones distort an average badly, and they also behave differently when selling — they are worth listing individually even if the rest goes as a job lot. Entering how many exceed £50 lets the calculator flag this rather than burying them in the average.
Worked example: two hundred board games in the loft
A collection built up over twenty years — around 200 games, mostly ordinary titles worth about £12 each, in very good condition and complete in their boxes. The owner wants them gone and is considering listing them individually on a marketplace at the usual 13% fees.
200 games at £12.00 each. This is the ceiling, not the answer.
Very good — light shelf wear only (×1) and complete with original packaging (×1).
Selling by online marketplace, individual listings, which typically returns 75–95% of private-sale value, less 13% in fees and commission.
That is £7.83 to £9.92 per item, and 83% of the catalogue figure at best.
Sold privately and patiently, the same collection might return £2,160.00 to £2,400.00 — roughly 1.2× what this route returns. That difference is what you are paying for speed and for not doing the work yourself.
For board games, completeness usually means the box, all components, rulebook and inserts. Estimates only — see three different values and understanding the result. Not suitable for probate or insurance.
The catalogue figure of £2,400 is the number most people would quote, and it is the one number here that will not happen. Condition and completeness leave it intact in this case, because very good and complete are the baseline — but individual marketplace listings return 75–95% of private-sale value, and the fees take another 13% off that.
The instructive comparison is what happens if the same collection goes to a bulk buyer instead: roughly £190 to £480, against £1,566 to £1,984 by patient individual listings. Four to eight times the difference, and it is entirely about method rather than about what is in the boxes.
The other number worth reading is the per-item figure. At roughly £8 to £10 net per game, individual listings clear the time test comfortably — 200 games at twenty minutes each is around 65 hours of work for something like £1,700, which is a reasonable rate. Had the average been £2 a game rather than £12, the same 65 hours would have returned under £300 and the bulk offer would have been the sensible choice.
Understanding the result
The output is a range, and the width of it is the point. A wide spread means the outcome depends more on how you sell than on what you own.
- The catalogue figure is not a target. Treat it as the ceiling that a patient, well-presented sale of every item individually might approach, and never quite reach.
- The gap between routes is the real finding. For most collections the difference between a bulk buyer and patient individual listings is several times over. That gap is what you are being paid for the months of work, so it is a legitimate trade, not a swindle.
- Per-item net is the number to sanity-check. If it works out at £1.50 an item and each takes twenty minutes to photograph, list, pack and post, you are working for well under minimum wage. That is the calculation most people skip.
It cannot see your items and knows nothing about which specific editions, pressings or print runs you have — the details that separate an ordinary copy from a valuable one. For probate, insurance, division of an estate, or any collection that might run to serious money, get a valuation from a qualified specialist. For anything genuinely rare, a specialist auction house will usually give an indication without charge, because they want the consignment.
What moves the value, by collection type
The arithmetic is the same everywhere. What counts as a valuable detail is not.
- Board games. Completeness is close to everything — a missing component can take most of the value, and buyers ask specifically. Out-of-print titles and original editions of games later reprinted are where the money sits. Punched but complete is worth far more than it sounds.
- Vinyl. Pressing matters more than title. The matrix or runout numbers etched near the label identify which pressing you have, and first pressings can be worth many times a later one of the same record. Sleeve condition and record condition are graded separately, and both are quoted in any serious sale.
- Books. For modern firsts, the dust jacket can be the majority of the value, and a jacketless copy of a valuable book is often worth a small fraction. Edition and impression matter — the number line on the copyright page is what to check. Ex-library copies and book club editions are worth very little regardless of condition.
- Comics. Grading dominates, and the difference between adjacent grades on a key issue can be substantial. Spine stress, colour breaks and whether it has been read at all are what graders look at.
- Video games. Complete in box beats loose cartridges or discs by a wide margin, and the manual is part of that. Sealed copies are a different market again, with its own authentication questions.
- Trading cards. Professional grading can multiply the value of a strong card and is a waste of money on a weak one, since the fee is the same either way. Condition assessment before submitting is the skill.
- DVDs and Blu-rays. Ordinary titles have very little value in bulk. The exceptions are limited editions, boxed sets, out-of-print transfers and anything from a specialist label.
- Model kits. Sealed and unstarted is the premium condition. An opened box with sprues intact is worth considerably less, and a part-built kit is usually worth very little to anyone but a parts buyer.
Common mistakes
- Pricing from asking prices rather than completed sales. Anyone can list an item at any price. What matters is what buyers actually paid, which most marketplaces will show you if you filter to sold listings.
- Averaging across a collection that is not uniform. A handful of valuable pieces and several hundred ordinary ones is not the same as everything being worth the average, and treating it that way misleads in both directions.
- Forgetting postage. Books and board games are heavy. On low-value items, postage and packaging can exceed the item's value, and marketplace fees are usually charged on the total including postage.
- Ignoring the time. Selling three hundred items individually is weeks of work. Cost it before deciding the bulk offer is unreasonable.
- Cleaning or repairing before selling. Amateur restoration reduces value more often than it increases it, particularly with books and comics. Leave it alone and describe it honestly.
- Assuming age means value. Old and common is still common. Scarcity plus demand creates value, and most mass-market items from any era have neither.
- Splitting a set. Complete runs and matched sets usually sell for more together than the sum of their parts.
Frequently asked questions
Why is a dealer only offering a fraction of what my collection is worth?
Because they are buying, not valuing. A dealer has to fund the purchase, store the stock, absorb the items that never sell, and wait — often months or years — for the right buyer for each piece. An offer in the region of a quarter to a half of private-sale value reflects that risk and cost. It is a genuine trade: they take on the work and the uncertainty, and you get the money now. Whether it is worth accepting depends on how much your time is worth and how quickly you need to be rid of it.
Should I sell items individually or as one lot?
Individually earns considerably more and costs considerably more effort. As a rough guide, if the collection contains a reasonable number of items worth more than about £20 each, listing those separately and selling the remainder as a lot captures most of the value for a fraction of the work. If almost everything is low value, the individual route rarely repays the time once postage, fees and packing are counted.
How do I find out what my items are actually worth?
Search completed and sold listings on the marketplaces where that category trades, not current asking prices. For most collecting fields there are also established databases and price guides run by collectors, which are more reliable than general valuation sites. Match the specific edition, pressing or printing rather than the title alone — that distinction is usually where the value lies.
Is a professional valuation worth paying for?
For an ordinary collection, no. For anything that might run into thousands, for probate, or for insurance on named items, yes. Specialist auction houses will often give a free indication of whether a collection is worth their attention, since they are looking for consignments. A paid written valuation is what you need where a figure has to stand up — insurance schedules, estates, and division of property.
Does grading a card or comic increase its value?
It can, substantially, but only on items already in strong condition. Grading costs the same whether the item comes back a high grade or a low one, so submitting borderline material reliably loses money. The skill is assessing condition accurately before you send anything, which is worth learning before paying for it.
What about insurance — is this the figure to give my insurer?
No. Insurers work on replacement value, which is what it would cost to buy the collection again at retail, and that is usually higher than what you would receive selling it. Most household policies also cap what they will pay for a single item or a collection unless it is specifically listed. If your collection is worth serious money, tell your insurer and ask what evidence they want.
Do I have to pay tax on selling my collection?
It depends on what you are doing and the amounts involved. Selling personal possessions you have owned and used is treated differently from trading, and there are specific rules and allowances for chattels and for capital gains. If you are buying to resell regularly, or the sums are substantial, the position is genuinely complicated and worth checking with HMRC's guidance or an accountant. This calculator makes no attempt to model tax.
Is what I enter stored?
No. Everything is calculated in your browser and nothing is transmitted or retained.
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References
These organisations publish the guidance behind this page.
- GOV.UK — guidance on selling personal possessions, chattels and capital gains
- HM Revenue and Customs — when selling becomes trading, and what has to be declared
- Royal Institution of Chartered Surveyors — professional standards for valuation, including for probate and insurance
- MoneyHelper — free impartial guidance on insurance cover and valuing possessions
- Citizens Advice — your rights when selling to a trader or through an online marketplace
External guidance changes. Check the current position at the source before relying on it for a decision that matters.