When Contagion Engine enters the battlefield, put a -1/-1 counter on each creature target player controls. {4}, {T}: Proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)
NM-Mint - $20.10
Lightly Played - $18.10
Moderately Played - $16.10
Heavily Played - $14.10
Damaged - $10.10
NM-Mint Non English - $20.10
Lightly Played Non English - $18.10
Moderately Played Non English - $16.10
Heavily Played Non English - $14.10
Damaged Non English - $10.10
Foil Prices
NM-Mint Foil - $20.70
Lightly Played Foil - $18.60
Moderately Played Foil - $16.50
Heavily Played Foil - $14.50
Damaged Foil - $10.40
NM-Mint Foil Non English - $20.70
Lightly Played Foil Non English - $18.60
Moderately Played Foil Non English - $16.50
Heavily Played Foil Non English - $14.50
Damaged Foil Non English - $10.40