Go to ebay, search for those cameras and look at the prices that cameras in similar condition ACTUALLY sold for, auction prices and buy it now prices are not an indication of market value, actual selling price is. The Pentax K-1000 might fetch a little more than you expect because it is an excellent student camera, and it is back to school time right now. I have no clue on the other camera.

Another good source of pricing and market value is www.KEH.com you might need to do some poking around, but I found a price for the K1000 body just by doing a quick check at KEH.

Good luck