Gauntlet of Power 255/301 (The List Reprints)

As this artifact enters, choose a color. Creatures of the chosen color get +1/+1. Whenever a basic land is tapped for mana of the chosen color, its controller adds an additional one mana of that color.

NM - $8.90
LP - $7.10
MP - $5.40
HP - $3.60
DMG - $2.20