Arena of Glory 215 (Modern Horizons 3)

This land enters tapped unless you control a Mountain. {T}: Add {R}. {R}, {T}, Exert this land: Add {R}{R}. If that mana is spent on a creature spell, it gains haste until end of turn. (An exerted permanent won't untap during your next untap step.)

NM - $11.34
LP - $9.50
MP - $6.48
HP - $4.32
DMG - $2.16