I bought both my intake CPS from Amazon for about $100.
They were marked with pretty clear marks from the subcontractor BMW uses and the instructions were in German. Also they worked flawlessly.
BMW e39 z3 e46 e53 CAMshaft position RPM Sensor OEM Brand NEW with 1yr WARRANTY
https://www.amazon.com/dp/B00AEY13P8..._bnDoCb11351SQ
If the ad says OEM it has to be or you can send it back. The probkem with Amazon ordering is the identical ASIN will be sold by different vendors so it's a crap shoot if you'll get an honest one.
I like to try to find the same vendor once I'm satisfied.