Thanks OP for this thread.
I was unaware of this thread and posted something similar in the 3-series forum, last week:
http://www.e90post.com/forums/showthread.php?t=739068
Thought you might be interested as it's another vendor carrying the TRW M3 Arms.
I've since googled them and they turn up elsewhere, but not sure what to make of the vendors selling them.
I'm thinking I'll eventually find them cheaper, as someone will put them on special or have a store-wide sale that will drop the price.