Dangermouse wrote:
The A 50mm f1.7 is a great lens - I have one in similar condition that I love using as it's tiny, sharp, and fast. The plastic aperture ring isn't nice, but with a DSLR you simply set it to A and don't touch it again. The focussing feels much nicer than a modern AF lens, with far more feel.

Price is a tricky one. I paid £42 for mine a couple of months ago but prices seem to have gone a bit mad of late and I did have the advantage of spotting a listing that was simply titled "Pentax 50mm". I saw a fungus-infested example hit £36 around xmas, which is utterly insane money for a less-than-perfect example. I don't think you paid much over the odds however, from looking at other listings.