When Horned Stoneseeker enters the battlefield, create a tapped Powerstone token. (It's an artifact with “{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.”)
When Horned Stoneseeker leaves the battlefield, sacrifice a Powerstone.
Near Mint - $0.10
Lightly Played - $0.10
Played - $0.10
Heavily Played - $0.10
Damaged - $0.10
Near Mint Non-English - $0.10
Lightly Played Non-English - $0.10
Played Non-English - $0.10
Heavily Played Non-English - $0.10
Damaged Non-English - $0.10
Foil Prices
Near Mint Foil - $0.20
Lightly Played Foil - $0.20
Played Foil - $0.10
Heavily Played Foil - $0.10
Damaged Foil - $0.10
Near Mint Foil Non-English - $0.20
Lightly Played Foil Non-English - $0.20
Played Foil Non-English - $0.10
Heavily Played Foil Non-English - $0.10
Damaged Foil Non-English - $0.10