Methodology
Real prices. Never invented.
A collection is only worth what cards actually sell for — not what an app's internal database wishes they were worth. Every number on Foilio is a reference estimate from open, attributed market data, shown with its source. This page explains exactly how each value is built and how to verify it yourself.
Where every price comes from
Foilio reads prices from free, openly-available catalog APIs and attributes each to its source. We never scrape marketplaces and we never invent or inflate a number.
Why honest pricing matters
The most common complaint about collection-tracker apps is inflated values: collectors have publicly documented single cards shown at many times their real recent-sale price, because the app values from a large internal database rather than the live market. That feels good until you try to sell — or insure — and reality bites.
Foilio takes the opposite stance: the market-trend price, attributed, with a link to verify at the source. A lower, honest number is more useful than a flattering, wrong one — especially when you're about to make a real decision with real money.
How each estimate is built
- Card value (search): the current market-trend reference for the exact printing, with a US (USD) / EU (EUR) toggle so you read the market you'd actually sell in.
- Grading ROI (grading): the raw reference price multiplied by a published, disclosed era uplift, minus real all-in PSA costs (fee + shipping/insurance). It's a transparent model estimate — not a sold comp — so you can sanity-check whether grading clears the cost before you mail a card.
- Booster-box EV (box EV): a Monte-Carlo simulation over per-rarity pull odds using trimmed average prices (so one mispriced outlier can't skew the result), reporting a P10/P50/P90 range rather than a single number — because a box is a distribution, not a guarantee.
- Collection value + P&L (collection): the sum of each card's reference value, compared against what you paid (your cost basis) for an honest unrealised gain/loss — not a hyped portfolio figure.
- Fee-aware net (sell + fee calculator): what you'd actually take home after marketplace and payment fees — the number that matters when you cash out.
What these numbers are not
- Not a record of what your specific copy sold for — they're current market-trend references.
- Not an appraisal and not financial advice.
- Scanning identifies a card; it does not authenticate or grade it.
- Always shown as reference estimates, dated to the current data — never stale figures dressed up as live.
Common questions
Where do Foilio's prices come from?
Every price is a reference estimate pulled from free, openly-available, attributed APIs — Cardmarket's EUR trend (via pokemontcg.io), Scryfall, YGOPRODeck, Lorcast, and TCGplayer-derived USD data. We never scrape marketplaces and we never invent a number. Each value is shown with its source so you can verify it.
Why is my card worth less on Foilio than on some other apps?
Some popular collection apps derive value from a large internal product database rather than current marketplace data, which can drift well above what cards actually sell for — collectors have documented single cards valued at many times their real recent-sale price. Foilio shows the open-market trend price and links you to the source, so the number reflects reality, not an inflated internal estimate. A lower, honest number is the point.
Are Foilio's prices accurate / can I trust them?
They are accurate as reference estimates of current market trend — not a guarantee of what your specific copy will sell for. Condition, edition, language and the exact printing all move the real price. Treat every Foilio value as a well-sourced starting point, confirm the exact printing, and check live listings before you buy, sell, or insure.
How often are prices updated?
Prices refresh as their underlying open APIs update (typically daily). Values you see are labelled as reference estimates as-of the current data, never stale figures presented as live.
Is Foilio free, and do I need an account?
Yes, it's free, and no account is required. Your collection is stored in your own browser, not on our servers. We use only open data and never sell your data.
Does Foilio give financial or investment advice?
No. Foilio is an unofficial fan tool that helps you identify cards and read reference prices. Nothing on Foilio is financial advice, an appraisal, or a guarantee of value.
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