When looking at KEH for a short to medium lens for my freebie K1000 body I see that prices are dam near as much as a AF lens for my primary carry Nikon. I really can't see spending so much on a lens for this body that I would like to occasionally carry with. Since I'm not covered in 24mm I checked and found I could find a better deal on a Nikon AF 2.8 and it's a hell of a lens. What justifies such high Pentax prices? Available quanities?