I see a Pentax PZ-1 on KEH for $39 in EX condition. That's a great deal I'd say, if you like K mount lenses. The PZ-1 (and successor PZ-1p) is an excellent camera, but kind of ugly. They have some as low as $9. That's a giveaway.

Older manual focus SLRs command higher prices, mostly due to much better build quality. Spotmatics used to be the secret bargains (and indeed the cameras still are) but the lenses have crept up due to M43 and Canon video guys using them.