If you are "serious" about selling it I would tell people to make you a "serious offer" and best offer by ??/??/2020 will own it. I would also include "if you are the highest offer you have 14 days to get it picked up or I'll move on to the next highest offer". To me that is being fair to everyone - fair to you because you have a chance to see where market actually is on the machine and fair to buyers because they can offer what they think it is worth (or what it is worth to them).
I don't know what to think as far as actual value but my best guess would be in the $7500 to $9000 range depending on how bad someone wants one at that point in time.