If you look at just body price vs features, I would suggest a Minolta Dynax/Maxxum 5. Every feature you could think of (motor drive, AF, wireless TTL flash, ultrasonic-focus support, matrix metering, all PASM modes, etc) but they're plasticky and don't have the fastest X-sync. Typical price is $10 to $20. If you want a tiny, light and full-featured SLR then it's an excellent option.
The only drawback is they take Minolta lenses (which are excellent) and Sony has been so successful in selling DSLRs compared to Minolta that the best lenses are getting quite pricy compared to Canon/Nikon options. A 50/1.7 or consumer-grade f/3.5-4.5 zoom will still be very cheap though.
The upside of that is that you can put brand new autofocus Zeiss glass (24/2, 85/1.4, 135/1.8, etc) on it, plus the 135 STF lens with bokeh-apodisation filter.