These days on Ebay you can usually pick up various K mount cameras for not much more then shipping. The Ricohs are some of the best values. Better speced then the Pentaxes. Cheaper. No cult bidding wars.
If you want basic with no frills then something like the KR-5 types. If you want everything but autofocus then the XR-M or XR-X camera. Same camera different name. With patience both should be had for less then $50 with a 50mm. The KR-5 maybe closer to $30.
That website has manuals for a whole bunch of K mount cameras.