No 10 here John, 25-30 afaik from the dealers. Done one of mine about a year ago and it's still fine but all depends on the condition of the piston (don't get a new one in the kit). If the piston is badly rusted then just get a complete new caliper!

http://www.realoem.com/bmw/showparts.do?model=AL32&mospid=47631&btnr=34_1013& hg=34&fg=10