What's wrong with my Film camera?

I have a Nikon N75 I got for my photography class and it made it all the way though almost. But now every time I try in put film in it. It just says error. I had my teacher look at it and A camera store and no one knows why? I feel like it would be an easy fix. Any ideas? If not i'm just going to keep the lens and sell the body for parts. What would be a good price for just the body?

The error message of death. Happened to one of mine once. It was less expensive to replace it than to repair it.