Used machinery, in very clean condition, typically goes for 20-40% off "MSRP". BUT, that is very subject to location, timing, and just plain luck. If you're in a hurry, mark it down. IF you're not, ask more, and see what offers you get. Luck is still probably the over-riding factor, as there is not a huge market for such things, and it's really not practical, or cost-effective, to ship, so you have to find someone local, or willing to travel to pick it up. Also consider how you'd get it out of your shop and into a pickup or trailer.
It took me years to sell my CNC knee mill (with ATC!), and it finally went for about what I paid for the original, manual, machine, But, at least it went to a nice young guy who I'm sure will put it to good use.
Where is the machine located?
Regards,
Ray L.