The focus ring on my 50mm rokkor is uncomfortably tight in the closest 1/3 of the focusing range. The lens hasn't been used in years and probably has never been serviced. I'm guessing the lubrication has degraded over time. How difficult is it to fix at home? If not, how much can I expect to spend to have a repair shop do it?
Frankly, for a lens that common and cheap, I'd take my chances with a "new" used one.