I had a line on a 2000xl with 8 outs, card reader, and 8mb ram for $600; I hesitated and he sold it on eBay. I think I may have dodged a bullet though. For $600 I could snag a TR-8, a Nord Drum 2, some Ableton plugins, etc
Basically I love the MPC workflow (coming from Maschine) but maybe an outboard hardware version would be redundant for me (actually, I know it is, I just get obsessed with hardware sometimes).