At the beginning of your upkeep, put a +1/+1 counter on Myr Prototype. Myr Prototype can't attack or block unless you pay {1} for each +1/+1 counter on it.
NM-Mint - $0.50
Lightly Played - $0.45
Moderately Played - $0.40
Heavily Played - $0.35
Damaged - $0.25
NM-Mint Non English - $0.50
Lightly Played Non English - $0.45
Moderately Played Non English - $0.40
Heavily Played Non English - $0.35
Damaged Non English - $0.25
Foil Prices
NM-Mint Foil - $0.70
Lightly Played Foil - $0.70
Moderately Played Foil - $0.60
Heavily Played Foil - $0.50
Damaged Foil - $0.40
NM-Mint Foil Non English - $0.70
Lightly Played Foil Non English - $0.70
Moderately Played Foil Non English - $0.60
Heavily Played Foil Non English - $0.50
Damaged Foil Non English - $0.40