Gt500

I have a chance to buy a, I think, 1976 GT500. It is complete, running. Comes with new crank seals, not installed, no biggie. Also new fork seals if seller can find them. Also comes with a clear title in sellers name. I usually buy bikes to either resell or part out. I have refurbed some and sold them. Anyone have an idea what one of these is worth? I know, whatever someone else is willing to pay. I am looking for a ballpark figure. I haven't looked at the bike yet and haven't seen the pictures yet, I should get those tonight. Seller is an older guy and sounds like he just needs to get it out of his way. He says he rides it about once a month or so around the block.