Selvala, Heart of the Wilds 116 (Commander: Lorwyn Eclipsed)

Whenever another creature enters, its controller may draw a card if its power is greater than each other creature's power. {G}, {T}: Add X mana in any combination of colors, where X is the greatest power among creatures you control.

NM - $8.80
LP - $7.10
MP - $5.30
HP - $3.60
DMG - $2.20