I just replaced these myself, in my driveway, in about two hours. I used Lemforder parts that looked identical to the OE parts, same numbers cast in and everything. I posted it here:
https://www.bimmerpost.com/forums/sh...php?p=27760240
Both bushings shipped to Canada for $80 tax and shipping included. Any shop charging more than $300 for this job is profiting handsomely!