I am struggling to comprehend why anyone would retrofit this. If you wanted it for the navigation then a tomtom or garmin would be 10 times better and a similar price, if you wanted it for smart phone connectivity then a Sena or similar would be better and cheaper.
A 2nd hand tomtom/garmin and a new Sena would be about the same price and infinitely more useful.
I was quoted £350 to fit. Apparently the Bluetooth unit is £243 + vat plus about an hours labour to install. It takes an additional hour (non-chargeable) to download and install the software.
My phone holder cost £15 plus a bit of home made bar and an additional £15 for the din-usb plug / cable so that leave me £300 in the pocket. Hmmmmm.
.... and when you suddenly, 3, 6, 12 months later decide you want a change of bike .... well that Garmin, Tom-Tom, phone, etc. simply moves with you.
If the integrated system comes as standard on a bike fair enough but the appeal of the relatively expensive retrofit route ... pass.