Look around on
www.realoem.com
You can find some pricing on there for parts at least. But labor hours wise it is a big job, probably about 4 - 8 labor hours total at shops labor charge rate = total job cost of over $1k. (labor hours depend on amount of damage)
If you are decent with the 'ol tool set you may be able to do it yourself, but it is a decently involved job as you can see in this recent thread...
http://www.xoutpost.com/x5-e53-forum/...ment-pics.html