http://www.miyatacatalogs.com/2007/1...r-special.html

Above is a link with more info on Miyatas. I can't seem to place yours but it looks like a 90s model. If it has a STP (splined triple butted) frame and the bike is in good shape, I'd say you got a pretty nice deal on it. On the other hand, I've never given more money to a seller for a bike. I presume if I saw a brand new Paramount for $20, I might give the person a heads up. However, I've never been in the situation before so who knows.