The round trip on a collectable card costs 44% of the ask on a $20-100 card, and never less than 44% at any price — and above $500, almost nothing trades at all.
A market-health read on Magic singles from the one dealer that publishes both what it charges and what it pays, built to test whether the marked price of a card is a price anyone pays.
Built after reading about fractional ownership of collectable cards. Card Kingdom is the only source in MTGJSON that publishes a buylist as well as a retail price, which makes a genuine round trip observable: one dealer's ask against its own bid, on the same card, on the same day, rather than a spread stitched from two venues that never trade with each other. Most of the answers cut against the case for treating cards as an asset. Nearly half of the printings the dealer sells it will not buy back at all, worst in the $100–500 range that anyone would fractionalise; two major venues quoting the same card the same day sit a third apart; two thirds of the basket's value sits in one card in a hundred; and at the expensive end, where TCGplayer's sales-derived price and Cardsphere's trade counts both go quiet, liquidity is something the dealer provides at its own spread rather than something the market supplies. One expected finding did not appear and is reported as the null it is: the stale-price smoothing that flatters art indices is absent, because repricing is lumpy but the jumps are large. A pre-registered test found that only price tier separates these cards into different assets; era, supply mechanism and rarity do not. A reprint event study with the Reserved List as its structural control failed that control and says so.