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 - $11,100
Lightly Played - $8,900
Moderately Played - $7,800
Heavily Played - $6,700
Damaged - $5,600
Near Mint Spanish - $11,100
Lightly Played Spanish - $8,900
Moderately Played Spanish - $7,800
Heavily Played Spanish - $6,700
Damaged Spanish - $5,600