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 - $7.70
LP - $6.20
MP - $4.60
HP - $3.10
DMG - $2.20