Spell Swindle is a rare Instant card from Ixalan Promos (PXLN), collector number 82p. Current market price: $1.94 (foil $6.50), TCGplayer market prices via Scryfall.
Counter target spell. Create X Treasure tokens, where X is that spell's mana value. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")