How Cardboard Deals works

Cardboard Deals finds Magic: The Gathering and One Piece Card Game cards listed below their going market rate, so you can spot a bargain without watching the marketplace all day. Each game has its own searches, its own card matching and its own prices. Here's what happens behind the scenes.

1. 1. We scan the marketplaces

   Throughout the day we poll eBay (UK and US) for Magic and One Piece listings, recording each one we see: raw singles and graded slabs for every game, plus sealed product (booster boxes, bundles, precons) for Magic.

2. 2. We identify the exact card

   Each listing title is matched to its precise printing by a parser written for that game, because sellers describe each game differently.

   • Magic: The Gathering: name, set, collector number and finish (foil, etched, borderless, showcase), using card data from Scryfall.
   • One Piece Card Game: the card code printed on every card (OP01-120) and the variant (parallel, manga, alternate art), using TCGplayer's catalogue.

   When a title could be more than one printing, we price it as the cheapest of them, so a discount is never overstated; a title naming a variant we can't place is left out. Graded copies are read for their company and grade (PSA, BGS, CGC, SGC).

3. 3. We build a market benchmark

   For every card we track a rolling price benchmark, kept separate for raw and graded copies so a PSA 10 is never averaged against an ungraded card. Magic prices combine TCGplayer and Cardmarket with recent eBay sales; One Piece cards are priced against the TCGplayer market, with recent eBay sales recorded beside it.

4. 4. We flag the deals

   When a listing's asking price sits a meaningful percentage below the benchmark, it becomes a deal — surfaced on the live feed, on its own deal page, and (in real time) through Discord and the app.

More questions? See the FAQ, or browse Magic cards or One Piece cards.