Just to add: The ones people are posting for $30 are NOT the ones I was talking about in the OP. The one in the OP has extra grips on it so you can do wider versions of all the exercises, to work your back more. It's the exact one sold on beachbody.com to go with P90x.
I live in a condo, and although the doors were too thin, I fixed this problem by getting two longer screws, and putting a spacer between the upward facing bars and the one that sits on the frame to shorten the distance. I also used the mounting brackets that are included (at least the one from treadmillfactory came with them, I can't speak to other places). Started P90x on Monday. As of today I can barely move!
I live in a condo, and although the doors were too thin, I fixed this problem by getting two longer screws, and putting a spacer between the upward facing bars and the one that sits on the frame to shorten the distance. I also used the mounting brackets that are included (at least the one from treadmillfactory came with them, I can't speak to other places). Started P90x on Monday. As of today I can barely move!