I have my Canon 50 1.4 up for sale, and unfortunately, it suffers from the common stuck focus issue. I bought this used off here in December 2013 and used it mildly since then, with the issue appearing about a year into ownership.
I followed multiple guides, including this Youtube video to attempt to repair it:
So far, I have disassembled and reassembled it probably 6+ times so far since the issue started occurring (to flatten the focus ring), and unfortunately as well, I managed to break off the switch that lets you put the lens on pure Manual Focus mode, so it is always on Auto Focus, although you are still able to do Manual Focus Override at anytime with no issue.
Throughout the focus range, from 0.45m to Infinity, it just does not focus buttery smooth. I would say it's about 70% smooth most of the time, so this is a lens you could enjoy if you don't mind taking your time to get the right shot, but I would not recommend buying my particular one if you plan to be shooting video. If it does get slow or sort of stuck, you just have to "massage" it by moving the focus back and forth throughout the range to make it smooth again. Taking it apart and putting it back together does help a bit, and this latest time is probably the best it has been working because I haven't tightened the screws where the focus ring slides on to 100%, probably 80%, which gives it some room to move more.
Glass has some visible dust, so I would give it a 7/10, but the exterior is pretty good condition, where I would give it an 8/10.
Overall, if you are interested, send me a PM
2) Both Caps
3) Hoya HMC 58mm UV Filter
4) Hoya 58mm ND8 Filter
Due to the fact that it isn't 100% all the time, I will do $60 USD PP Gift'd (I'll cover the shipping), and will ship via USPS Priority Mail to the Continental US Only