Even the dealer service department admitted that the Volk-E was silly expensive. I like "factory" too but not at those prices or close.
I had my local installer install Blue Connect ( 2nd car in a row with this ) and I am very happy. Installed right into the headliner above driver ( which is easier in carls like mine without the sunroof ). One button to activate to call or answer, everything that follows is voice command which works well ( very good speech recognition ).
Actually, it's two buttons, one on the steering wheel to mute the radio, second to acivate Blue Connect to answer or initiate call. Still very easy and simple to use.
I have also had good luck with Parrot 3100 series ( now an older model ) on an earlier vehicle. Some of the newer Parrot stuff has really nice technical features if those are of interest, including the display of what number is calling you if not "blocked". Disadvantage IMHO is that such units need to mount hanging on your dash someplace which I don't prefer. It's all what you like and choose.
S