Is the wiring completely intact and not at all frayed? Plug is good? My biggest fear with used machines is always the fire hazard, or at the very least, a shock hazard. Of course they can be rewired, but unless you can do it yourself, that'll run you some money from a pro.
If it were me, I might give $5-10. I paid $7 for a fully working, vintage Kenmore from Goodwill for $7 a couple years ago. Have never used it a backup so I'm content with the amount.