I bought one from Sears, inexpensive but not very sturdy and makes a lot of noise. Don't draw any conclusions about them from ones you've used in a gym those are very expensive.
My first one broke numerous times and they weren't on top of sending me the correct parts. For example one time I finally got them to come down and see that a peice was broken so they replaced that part but since it was part of a newer model the screw didn't fit....and every time they had to come down was a couple weeks minimum. Eventually something broke that thy couldn't fix and they replaced the whole thing. However it's a very lengthy process, which is extremely frustrating if excersizing is part of your daily routine.