Howdy

Not sure exactly who manufactures them, didn't really pay attention to any markings on shaft, box it came in was nondescript.

They do seem to have a confusing price structure, they list 4 as you have said, they differentiate between right and left, and Axle's for 3.0 and 4.4, sure look at the the pricing they have for Porsche cabrio hood motors, all over the place

The day I purchased mine they had a 10%-off sale, and that only ran for 24 hours!, I picked cheapest pricing availabe for my car, and let them look after the rest, quality was very good, no real visable difference between it and the BMW one that came of the car with the exception of a few missing BMW roundels
Has performed faultlessy though, my wife drives the X, and takes a spirited drive across the dublin mountains every day on her way to work, shocking roads, big potholes, actually not much of a road at all, so its no motorway cruiser, if it was bad quality it'd be stuffed by now.

I figured at the price they are selling them, its nearly as cheap to change the shaft than repair the CV boot, and if your CV is clicking you haven't got much choice, Dealer price here in Ireland for a genuine CV Shaft was approx €700 ($1000)