Key takeaways
- A value estimate is a claim about a market at a moment, not a property of the object, so two tools reading different slices of that market can disagree without either being wrong.
- Fair market value has a formal definition - the price a willing buyer and willing seller would agree on, neither compelled to act and both reasonably informed - and comparable sales are weighted by similarity, recency and whether the sale was arm's length.
- Economic research documents persistent price dispersion for identical goods even between stores that are equally expensive on average, which means variation is a normal feature of markets rather than evidence of a broken data source.
- Printing variant is the largest avoidable source of divergence in trading cards: normal, holo and reverse holo copies are separate goods with separate prices, and averaging them produces a number that describes no card.
- An app estimate is not an appraisal. Professional appraisal practice carries its own national standards, and an on-device figure is a starting point for a decision rather than a valuation you can rely on as one.
Hold one card, open two apps, and you can easily get two different numbers. The usual reaction is to decide one of them is broken. A better starting assumption is that both are summarising a real market and summarising it differently, because a value estimate is a claim about what strangers recently paid, not a measurable property of the object in your hand.
Once you see the estimate as a summary of transactions, the interesting question stops being "which app is right" and becomes "which transactions is each one looking at, and do they resemble my sale?"
A price is a claim about a market at a moment
Every card value estimate is built the same way in outline: find recent sales of something sufficiently similar, decide which of them count, and summarise them into one figure.
Each of those three steps contains choices, and the choices are where the divergence lives.
- Which marketplaces count. A card trades across auction sites, fixed-price listings, dealer inventories and private sales. Including or excluding any of those moves the number.
- How recent counts as recent. A seven-day window and a ninety-day window describe different markets when demand has moved.
- What "similar" means. Condition, printing, language, edition markings and grading status all create sub-markets within a single card name.
- Which outliers survive. One unusually high sale can drag a mean substantially; a median ignores it entirely.
- What is included in the price. Shipping, fees and taxes are sometimes inside the figure and sometimes outside it.
None of those is a mistake. They are reasonable, defensible design decisions, and different tools make them differently.
Fair market value has a definition, and it is stricter than it sounds
There is a formal version of what these estimates are approximating. US tax guidance on valuing property defines fair market value as the price property would sell for on the open market between a willing buyer and a willing seller, with neither compelled to act and both having reasonable knowledge of the relevant facts.
The same guidance is explicit about how comparable sales should be weighted, and the criteria transfer neatly to cards: how similar the comparable is to the item being valued, how close the sale was to the valuation date, whether the transaction was at arm's length, whether it happened in the same market, and what conditions prevailed at the time. It also notes that an appraiser relying on comparables should document the adjustments made and prefer the comparables needing the fewest.
Read that list against a card price and you can see why estimates diverge honestly. A sale from four months ago in a different country, bundled with three other cards, is a comparable — a weak one. How much weight a method gives it is a judgement call that reasonable methods make differently.
Dispersion is normal, even for identical goods
It is tempting to think a well-functioning market should converge on one price. Research says otherwise, and the finding is robust enough to be worth carrying around.
A Federal Reserve Bank of Richmond working paper on relative price dispersion documents that stores which are, on average, equally expensive nonetheless set persistently different prices for the same good in the same market and period. The authors attribute this to deliberate pricing strategies that separate buyers who consolidate purchases at one store from those willing to shop around.
The lesson for collectors is not about supermarkets. It is that a single "true price" for an identical good frequently does not exist even in mass-market retail, where the goods really are interchangeable and the data really is plentiful. A card market, with fewer transactions, greater condition variation and no central reporting, will not do better.
Variant is the divergence you can actually control
Most of the reasons above are outside your hands. One is not.
Normal, holo and reverse holo copies of the same card are separate goods that trade at separate prices. Any estimate that averages them describes no card that exists. TCG Card Grading Scanner Value — our own app, built by Reign Creative — prices those printings separately and keeps the selected variant visible with the result, precisely so the number is attached to something specific.
When two figures disagree badly, check the variant before anything else. It is the most common single explanation, and it is the one you can settle by looking at the card. Reverse holo and holo printings covers how to tell them apart when the difference is not obvious under room lighting.
An estimate is not an appraisal, and the gap is structural
This distinction matters more than it sounds. Professional appraisal in the United States operates under the Uniform Standards of Professional Appraisal Practice, the national standards covering real property, personal property, business valuation and mass appraisal, published by The Appraisal Foundation. An appraisal under those standards involves an identified appraiser, a stated scope of work, documented reasoning and accountability for the conclusion.
An app estimate has none of those things by design. It is a fast, informational figure based on available third-party market information for the matched card and variant. It can change, may be unavailable for some cards, and is not a guaranteed sale price, an offer or an appraisal. That is not a shortcoming to be fixed; it is a different product.
How to read two disagreeing numbers
A short procedure resolves most cases without needing to declare a winner.
Confirm you are comparing the same card. Same set, same collector number, same printing variant, same language and edition markings.
Look at the spread, not the midpoint. Two estimates four dollars apart on a nine-dollar card tell you the card is low-value and imprecisely priced, which is all you need. Two estimates eighty dollars apart on a two-hundred-dollar card tell you to look at actual recent sales yourself before acting.
Decide what the number is for. A rough total across a collection tolerates wide error bars. A decision to spend money — submitting for grading, for instance, where costs and tiers come into play — does not, and whether a card is worth grading should be worked out against the low end of the range rather than the high one.
Let time settle the rest. Thin markets are noisy. A figure that moves week to week on a card with few sales is telling you about sample size, not about value.
More writing on the studio's utility apps sits under video and utility apps.
Good to know
Frequently asked questions
Why does the same card show two different values?
What does fair market value actually mean?
Is a scanner estimate an appraisal?
How much does the printing variant matter?
Sources
- Publication 561, Determining the Value of Donated Property (opens in a new tab)Internal Revenue Service — accessed
- Relative Price Dispersion: Evidence and Theory (Working Paper 16-02) (opens in a new tab)Federal Reserve Bank of Richmond — accessed
- Uniform Standards of Professional Appraisal Practice (USPAP) (opens in a new tab)The Appraisal Foundation — accessed
About the author
Reign Creative LLC — The independent app studio that builds the apps covered on this site and publishes every article here. On Google Play it publishes as Reign Collective Apps.
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