Your market will tell you what it's worth as they location matters. I had an '88 Trek 1000 - I paid a case of beer for it.
It was a good bike that I commuted many miles on for a number of years until I built a new commuter and gave it away. The only issue I had was the Matrix rim on the rear started hairline cracking at the spokes (panniers on, crappy midwestern roads) although that wheelset is still in use on my sons bike