Port installed items are at MSRP. I forget but I think installation is free, best to ask your SA.
If getting multiple items it might also be cheaper getting a package? Not sure of the current choices or where to learn more about them.
http://f87.bimmerpost.com/forums/sho....php?t=1299524
http://www.bmwblog.com/2016/08/30/bm...ariety-models/