I have a Diamondback with a six inch barrel that I bought about 15 years ago. I don't want to sell it, but I am curious what a good used one is now worth?

go to www.gunbroker.com and search for it....that will give you a pretty good idea.

I just bought a 4" @ 95% for $500 he wanted $600. They go for a lot more and not many around. Give it 10 yrs. and they'll go out of sight.