I just sold this used Trek 1000 in 43cm /650c wheel size for $300.

It's actually a pretty decent ride, with Sora brifters & triple crank. Sold to a guy who bought it for his two early teen boys - amazingly, it fit both. Now they had a "real" bike like Daddy, and they couldn't be happier. The flashy frame and red wheels don't hurt the kid appeal either.