Original Peavey 5150 amp head?

How much are they worth these days. I have the original head , not the II model, and i bought it from a local shop used, but it hasn't been used much - the thing is in pristine condition with not a scratch on it , and not one nick in the Tolex covering. This is the one with 4 6L6GC power tubes and 5 12AX7A tubes for the preamp section. It works fine alright, but i don't use it much because it's a different tone than my main amp i used for years , and i never got used to the 5150's sound. I'm toying with the idea of selling it or even trading for something else , but at the moment i'm in no hurry. So , who knows what this head is worth?