Contagion Engine 145/249 (The List Reprints)

When this artifact enters, put a -1/-1 counter on each creature target player controls. {4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

NM - $27.60
LP - $22.10
MP - $16.60
HP - $11.10
DMG - $5.60