+1: Create a tapped Powerstone token. (It's an artifact with “{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.”)
−1: Pay any amount of mana. Look at that many cards from the top of your library, then put one of those cards into your hand and rest on the bottom of your library in a random order.
−7: You get an emblem with “Tap an untapped artifact you control: This emblem deals 1 damage to any target.”
Near Mint - £1.00
Lightly Played - £0.90
Moderately Played - £0.70
Heavily Played - £0.50
Damaged - £0.30
Near Mint Non English - £1.00
Lightly Played Non English - £0.90
Moderately Played Non English - £0.70
Heavily Played Non English - £0.50
Damaged Non English - £0.30
Foil Prices
Near Mint Foil - £1.30
Lightly Played Foil - £1.10
Moderately Played Foil - £0.90
Heavily Played Foil - £0.70
Damaged Foil - £0.40
Near Mint Foil Non English - £1.30
Lightly Played Foil Non English - £1.10
Moderately Played Foil Non English - £0.90
Heavily Played Foil Non English - £0.70
Damaged Foil Non English - £0.40