After receiving a quote for over $1000 from the dealer I decided to do some shopping around. The local shop I use to go to before getting the X5 always did great repairs on my other cars, so I figured I would give them a shot. I ordered the parts through Tischer BMW ($150), and the local shop only charged $539 to replace the inner and outer boots on both sides, $689 total.

The rear output seals are leaking on the rear differential, so I ordered the seals from Tischer ($30), and the shop will be replacing the seals and flushing the fluid next week, $425.