Nightmare Lash 219/306 (Mirrodin)

Equipped creature gets +1/+1 for each Swamp you control. Equip—Pay 3 life. (Pay 3 life: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

NM - $17.30
LP - $13.90
MP - $10.40
HP - $7.00
DMG - $3.50