Prohibit is a common Instant card from Duel Decks: Jace vs. Vraska (DDM), collector number 25. Current market price: $0.16, TCGplayer market prices via Scryfall.
Kicker {2} (You may pay an additional {2} as you cast this spell.) Counter target spell if its mana value is 2 or less. If this spell was kicked, counter that spell if its mana value is 4 or less instead.