What kind of car do you have? Try www.bimmerspecialist.com
. If you call the guy, he'll give you a quote for an aftermarket part. A German company called Lemforter makes control arms for BMW. If you see the BMW part and the aftermarket part, they have the same raised lettering aside from the BMW logo and part number being shaved off. The quotes for my e39 540 were $220 aftermarket vs $340 dealer. You may be able to find one for less from another manufacturer. Control arms aren't cheap though.