Bought my 396 at The GPS Store about a month ago -- $249. The price goes up and down, so you have to keep tabs.
As for mounting, if you do NOT want to hardwire, you can shave one corner of the mount off, leaving a 3-screw attachment (works just fine - I also did this with my older 350, and held up for years w/o issue). If you'd like a picture of my modification let me know.
There is no issue with charging it in the existing power port of the 2017. I have a dual USB insert, and I can charge both the 396 and my phone. The power port is attached to a 3A fuse, which I've replaced w/ a 5A (I've already checked, and there is NO issue w/ doing this. The associated cabling will handle 5A easily).
As for the 396, I'm loving it. Much less glare than the 350, more features, not the least of which is the "Adventurous Route" setting. I live north of Atlanta -- mountain road biker's paradise. I'll take a ride and make an effort to get lost... Then set it to route me home... With the Adventurous Route setting, it's already taken me down roads I've never been on before... It's a blast...
2017 Pearl White 650[/B]
AdventureTech lowering links and GPS mount
AdventureTech +2" SS braided brake line
GPI spools, SW Motech risers
Givi XS307 Tanklock bag and Givi 46L top case
Suzuki hard case saddlebags