comes down to:
is it the rack or the keyboard version?
the rack goes for more (probably because it's much lighter than the metallic/steel keyboard
anyways, I've seen them ranging from $500-$2000, so there really is no telling.
MnM, MD UW, DSI MEK, Polysix, SH-101 (red), 707, CR-8000, KPR-77, Yamaha C1 Music Computer, Synare PS-1, FX, mixers, some more stuff..