Food Chain is a rare Enchantment card from Mercadian Masques (MMQ), collector number 246. Current market price: $51.50 (foil $423.00), TCGplayer market prices via Scryfall.
Exile a creature you control: Add X mana of any one color, where X is 1 plus the exiled creature's mana value. Spend this mana only to cast creature spells.