Boulder Salvo is a common Sorcery card from Oath of the Gatewatch (OGW), collector number 102. Current market price: $0.14 (foil $0.07), TCGplayer market prices via Scryfall.
Surge {1}{R} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.) Boulder Salvo deals 4 damage to target creature.