Caged Sun CM2-178/5075 (The List Reprints)

As this artifact enters, choose a color. Creatures you control of the chosen color get +1/+1. Whenever a land's ability causes you to add one or more mana of the chosen color, add an additional one mana of that color.

NM - $7.70
LP - $6.20
MP - $4.60
HP - $3.10
DMG - $1.60