Curse of Opulence is a uncommon Enchantment — Aura Curse card from Murders at Karlov Manor Commander (MKC), collector number 150. Current market price: $3.84, TCGplayer market prices via Scryfall.
Enchant player Whenever enchanted player is attacked, create a Gold token. Each opponent attacking that player does the same. (A Gold token is an artifact with "Sacrifice this token: Add one mana of any color.")