I might be able to get a 1980 cb 650 for 750, I really want a 750 but they are going for 1500 plus in my area. I have a 550 k I'm considering selling. Why are the 650's so devalued vs a 550 or 750.
1: the 650 is a tweener bike. It's not that it is a bad bike but due to being considered a tweener it carries less value. Most people classify it as a rebel.
2: the 550 four has a cool factor. It looks/feels like a European bike of the 60s. Cool is cool.
3: I'd the 650 is in nice, clean, presentable condition buy it. You live in CT. That 650 should sell for over $2000 as long as it is nice, clean and presentable. And yes it must run. If ever I can buy a nice running bike for under a grand I will. A quick sale on these bikes is $1500. It's an easy money maker for you.
4: if a 750 is what you want, wait for it. Your 550 is cool so at least you have a cool ride while you wait. Also you could use your profit from the 650 to help buy a 750.
That is my $0.02 on this