At the beginning of your end step, create a tapped Powerstone token. (It's an artifact with “{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.”)
{6}: Draw a card and put a +1/+1 counter on Geology Enthusiast.
Near Mint - $0.30
Lightly Played - $0.20
Played - $0.20
Heavily Played - $0.20
Damaged - $0.20
Near Mint Non-English - $0.30
Lightly Played Non-English - $0.20
Played Non-English - $0.20
Heavily Played Non-English - $0.20
Damaged Non-English - $0.20
Foil Prices
Near Mint Foil - $0.80
Lightly Played Foil - $0.70
Played Foil - $0.60
Heavily Played Foil - $0.50
Damaged Foil - $0.40
Near Mint Foil Non-English - $0.80
Lightly Played Foil Non-English - $0.70
Played Foil Non-English - $0.60
Heavily Played Foil Non-English - $0.50
Damaged Foil Non-English - $0.40