I very nearly bought the one they have at KEH but $525 is a bit steep, even for this lens in excellent condition. I went with the more sensible 150 PS in similar condition at Adorama (for much less than half the price). That doesn't mean I still don't want the 180!
Ditto - I have nearly pushed the button on that one @ KEH a few times. Instead, I bought a 110 macro. This just means I get a bit more intimate with my subjects!