Glory-Bound Initiate 16/269 (Amonkhet)

You may exert this creature as it attacks. When you do, it gets +1/+3 and gains lifelink until end of turn. (An exerted creature won't untap during your next untap step.)

NM - $1.50
LP - $1.20
MP - $0.90
HP - $0.60
DMG - $0.40