Why every price should show its source

Ask a tracking app where a price came from and most cannot tell you. That is a problem for a collector deciding whether to sell, and a bigger problem for anyone using the number to insure, trade, or settle an estate. SlabX shows the source next to every price, and here is what those sources are.

Catalog prices

• Magic: The Gathering: TCGplayer and Cardmarket prices, by exact printing, through Scryfall.
• Pokémon: the Pokémon TCG API for search, with TCGdex for refreshes, both keyed to the same card ids.
• Yu-Gi-Oh!: YGOPRODeck, which carries TCGplayer, Cardmarket, and eBay figures.
• Disney Lorcana: Lorcast. Ravensburger's policy does not allow Lorcana prices behind a paywall, so they are free in SlabX and always will be.
• One Piece Card Game: the OPTCG catalog, refreshed daily.

Sold listings

Sports cards, graded cards, and anything without a catalog price use recent eBay sold listings: the median of recent sales with the outliers trimmed. These are labeled as estimates, because that is what they are. A median of five sales is not the same thing as a market price from a catalog that clears thousands of transactions, and pretending otherwise would break the first rule.

Your own number

Any card can carry a manual value. When it does, the app says the number is yours, not the market's, and it never mixes the two in a total without telling you.

Why this matters more for graded cards

A single grade step can move a price by a multiple, not a percentage. That is exactly where an unsourced number does the most damage. When a graded value in SlabX comes from sold listings, the plan is to show the actual sales behind it, date, platform, and grade, so you can judge the comps yourself.