Carpet of Flowers 240 (Urza's Saga)

At the beginning of each of your main phases, if you haven't added mana with this ability this turn, you may add X mana of any one color, where X is the number of Islands target opponent controls.

NM - $11.90
LP - $9.50
MP - $7.20
HP - $4.80
DMG - $2.40