Crooked Scales is a rare Artifact card from Mercadian Masques (MMQ), collector number 291. Current market price: $1.62 (foil $15.31), TCGplayer market prices via Scryfall.
{4}, {T}: Flip a coin. If you win the flip, destroy target creature an opponent controls. If you lose the flip, destroy target creature you control unless you pay {3} and repeat this process.