How much do you think a 10 karat gold ring from 1955 would be worth ?

This is kind of a followup to an earlier question I posted, at the time the first question was put up, I had not known about the karat rating. I was offered $ 15 (!!!) by some jeweler who "appraised" the ring, but I umed that was an attempted con job. Also, are what it is worth, and what you will actually get for it ( in view of the would be swindler I mentioned ) two different things ?