I have one from my film days and loved it but the range was a bit weird on DX (I shoot mostly landscapes) so I did not use it much on my DX bodies and it sat in the camera bag a lot.
I live in a humid environment and when I got the lens out to fit onto a new FX body a few months back it had sadly developed fungus spots on some of the internal lens elements.
It was quite easy to dismantle and clean but will never be quite the same again because the fungus damages the lens coatings and will eventually regrow. The spores will also enter the camera body and "infect" other lenses in time.
The point of this story is that many of these lenses are quite old now and may end up on the market due to not being used much (like mine). So before fitting to the camera, check the lens carefully with the aperture held full open and look into a light source from an oblique angle. move the zoom and focus rings around....if there is dirt or fungus inside you'll see it.