I have an M3 that needs tubes and the vibrato scanner adjusted, but I got lucky with that too.
I paid exactly $5.00 at Goodwill for it. I think everyone there either didn't know what it was or - more likely - didn't care.
It was the end of the day on a Friday and they were more interested in getting home.
I told them I'd be willing to pay more, because it's a charity and certainly the donor might be annoyed it was going for so little.
But they looked at me like I had two heads and wouldn't listen. I gave up try to reason with them and just paid the $5.00 (thinking I was probably becoming annoying). Yes, it was a bargain, but it was also a bittersweet experience.
I wonder how often other decent items just get overlooked or even trashed because people think it won't sell..