I would check the sites that tomctx listed although it is aaarims.com not aarims that is where I bought mine from I actually just finished putting htem on, warming up a bit right now. I am going to go wash it and take some pics.
Your best bet(if you can wait a bit) is to find some used wheels not new. My dad has a knack of finding great deals. He got a set of bmw oem wheels from the 540(they were going on a 530) for like $450. They are worth around that per wheel. He also found a set for his M3 for $400, they are MK motorsports and go for $550 a wheel. Used is the cheapest. Check the classifieds on here, bimmerforums and such. Also talk to your dealer and bmw mechanics they have alot of contacts with customers that may be loking to sell some wheels. That is how my dad got both of his pairs cheap.
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