I found an older Zykkor 135mm lens while cleaning out my office that I believe was for a Pentax K1000. It's in very good condition and I'd like to what it could be worth. A guy I work would be interested in looking at it if it fits his new K-x. I have not been successful in finding any prices or values online yet, so I thought I'd see if anyone here has any suggestions. I tried ebay, but there aren't any listed.
The lens specs are: ZYKKOR MC AUTO, 1:2.8, 135mm macro, no. 804381
look on E-Bay or at KEH.com. In all honesty probably between 5 and 25 dollars. I think the lens brand is an "off brand". Even prime lenses for older film cameras are almost valueless now. Third party lenses are even more so. Sorry. Check this link.