1982 is a somewhat unique year.
I believe it was the last year for the manual clutch.
After that they were all automatics like the Z50.
I have no idea how many were made though but someone told me a while back that Honda made a total of like 150,000 CT70s vs over a half-million Z50s total (I don't know if that's accurate though).
It is definitely worth some decent $ if it is in nice shape. With 500 miles, it's gotta be worth at least $1000 (probably a lot more).