According to a search I had BMW do at Budds, you CAN order these through BMW (they are very limited though). I can't prove this but it's what I was told when I purchased a double spoke rear for my car (two weeks ago). They had a limited quantity of stamped & staggered in stock (Vancover warehouse). the price of them new is over $1200 each (rim alone).
Your price with tires is excellent - I'd pay that for those rims (in good condition).
"I never try anything; I just do it. Wanna try me?"