📊 How We Price Cards
One Piece and Pokémon cards are priced from different sources. Here's exactly how we determine each one.
1. One Piece Prices (Japanese shops)
Sources: Suruga-ya, yuyu-tei and Card Rush — Japanese card shops' own selling prices, in yen
Updated: About weekly (a new scan runs when prices are more than 7 days old)
Updated: About weekly (a new scan runs when prices are more than 7 days old)
- Cheapest in-stock listing. The price shown is the lowest price among the shops that have the card in stock. Out-of-stock listings are ignored because they are often old and far too low.
- Sold out = ≈ last price. If every shop is sold out, we show the last price the shop listed, marked ≈. Sealed boxes and packs work the same way.
- Approximate versions = ≈. Each version (regular print, parallel, reprint) is priced separately. When a shop can't tell two versions apart and lists one price for both, that shared price is marked ≈ (approximate) until the exact version is priced.
- English-only cards are unpriced. Cards that exist only in English editions (not on Bandai's Japanese card list) show no price — a Japanese shop price for the same number belongs to a different card.
- No guesses. A card with no shop listing shows no price, rather than an estimate from its rarity.
- Boxes vs packs. Shops sell sealed boxes, not single packs, so a pack price is the box price ÷ packs per box (24, or 10 for PRB premium boosters), marked ≈.
2. Pokémon Prices
- Japanese vs English cards (JP / EN). The search lists both Japanese releases and English (international) releases, so any collector can record their whole collection. Every Pokémon card carries a small JP or EN label, and the search has a Language filter (All / Japanese / English).
- Japanese shops first (coming). Japanese cards will be priced mainly from Japanese shops (Card Rush and yuyu-tei), the same way as One Piece: cheapest in-stock listing, in yen. Our scanner for these shops is being built; sealed Pokémon boxes and packs already use Card Rush prices.
- Overseas reference until then. When a card has no Japanese shop price, we show the overseas reference from TCGdex: the TCGplayer market price (USD) × 150, or else the Cardmarket trend price (EUR) × 162. The card popup says "Overseas reference" when this is the case. Overseas prices can be far from what a Japanese shop charges.
- Weekly refresh. TCGdex prices are refreshed automatically every week (Sunday) by GitHub Actions. Set pages and top lists are rebuilt from the same data.
- Shared listings = ≈. Sometimes one Cardmarket listing is used for several different cards (e.g. a promo and its stamped versions). Those prices are marked ≈ and left out of the top-card lists, because the price isn't that card's own.
- One rule everywhere. Search, collection, set pages and top lists all use the same price function, so a card shows the same price on every page.
✅ Overseas reference pros: real marketplace data that covers most cards
⚠️ Limitation: international collector prices, not the Japanese domestic market
⚠️ Limitation: international collector prices, not the Japanese domestic market
3. JP Flea Market Target
Source: Manual research at Tokyo flea markets, Hard-Off, Book-Off
Updated: Periodically based on personal hunting experience
Updated: Periodically based on personal hunting experience
Japanese domestic prices are typically 30-50% lower than international market because:
- Local supply — Cards are everywhere in Japan (attics, grandparents' houses)
- Seller knowledge gap — Flea market vendors often don't research card values
- No export markup — No shipping, customs, or reseller margins
- Different demand — Japanese collectors have different preferences than Western market
4. The "Buy Under" Threshold
The 💰 Buy under ¥X tags on the One Piece cheat sheet represent a conservative target for a good deal at Japanese flea markets. This is NOT the average price — it's the price where you're getting clear value.
Formula (rough):
Buy Under ≈ US Market × 0.5 to 0.7
Example: $100 US market → ¥7,500-10,500 buy target
Buy Under ≈ US Market × 0.5 to 0.7
Example: $100 US market → ¥7,500-10,500 buy target
5. Why This Arbitrage Exists
⚠️ This guide exists because of information asymmetry. Flea market sellers in Japan often don't know (or don't care about) international collector prices. This won't last forever — as more people use guides like this, the gap will shrink.
6. Limitations & Disclaimers
- Prices fluctuate — use these as guidelines, not guarantees
- Condition matters enormously — our prices assume "played" condition
- Rare cards have thin markets — one sale can swing prices 50%+
- We may be wrong — always do your own research on big purchases