I just got a mint, and by mint I mean almost new like 100mm F2.8 Macro(gen 1) for $180. Only problem with the lens is the AF/MF switch is broken into 2 pieces and I needed to move it back and forth with a key or some other similar shaped object. I epoxied the switch back on and it works perfectly. It is amazingly sharp, and the focus is just as fast as the newer 100mm macro, just a little, very little nosier then the USM version.
I shall post images when I use it at school Thursday to shoot an assignment.