Unstable Amulet 142 (Modern Horizons 3)

When this artifact enters, you get {E}{E} (two energy counters). Whenever you cast a spell from anywhere other than your hand, this artifact deals 1 damage to each opponent. {T}, Pay {E}{E}: Exile the top card of your library. You may play it until you exile another card with this artifact.

NM - $1.90
LP - $1.50
MP - $1.10
HP - $0.80
DMG - $0.70