Well, since starting this thread last night my son passed on a CL link to a '75 750 so I've traded a couple emails with the guy. Started out quoting a KBB number of just over $2K. Of course, that's for a dealer (as if these are sitting on dealers floors), for a completely refurbished bike ready to hit the road, including the dealer mark up and before any negotiation. Bike has a good title but hasn't started in 5 years, needs new tires, has surface rust; you've seen it all before.
So I get back to him with what it will need before the "unknowns" since it won't start. Says his top offer has been $850 but most have been $200 to $400. It looks all original, the paint looks good, he says the tank has no rust and you know, just a little TLC. Maybe so. He claims to have worked on bikes for 20 years and has raced them for 15. So I ask you, why would he neglect one for five. No response to my questions about if it was put up for storage properly.
I'm gonna sit on it for a day or so. I already have this same year/model 750, it and it just may be that if it's not a runner, the parts would be a good swap for my current runner.