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 - $11.40
Lightly Played - $9.10
Moderately Played - $8.00
Heavily Played - $6.90
Damaged - $5.70
Near Mint Spanish - $11.40
Lightly Played Spanish - $9.10
Moderately Played Spanish - $8.00
Heavily Played Spanish - $6.90
Damaged Spanish - $5.70