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.)
Near Mint - $5.50
Lightly Played - $5.25
Moderately Played - $4.00
Heavily Played - $3.25
Damaged - $2.25
Near Mint Non-English - $5.50
Lightly Played Non-English - $5.25
Moderately Played Non-English - $4.00
Heavily Played Non-English - $3.25
Damaged Non-English - $2.25