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 - $11.60
Lightly Played - $10.40
Moderately Played - $9.30
Heavily Played - $8.10
Damaged - $5.80
NM-Mint Non English - $11.60
Lightly Played Non English - $10.40
Moderately Played Non English - $9.30
Heavily Played Non English - $8.10
Damaged Non English - $5.80
Foil Prices
NM-Mint Foil - $18.50
Lightly Played Foil - $16.70
Moderately Played Foil - $14.80
Heavily Played Foil - $13.00
Damaged Foil - $9.30
NM-Mint Foil Non English - $18.50
Lightly Played Foil Non English - $16.70
Moderately Played Foil Non English - $14.80
Heavily Played Foil Non English - $13.00
Damaged Foil Non English - $9.30