$3,500 for a new tranny?! It's better than having to foot the entire bill. I'd be curious if the solenoid change would have fixed your problem. Either way you are getting a new tranny and that is sweet.
2014 550i xDrive, Alpine White, Black Merino, Anthracite Wood, M Sport, Premium, Executive, and Cold Weather Packages, HUD, Ceramic Controls, Comfort Access, Sport Automatic Transmission, 4 Zone, Soft Close Doors, Power Trunk, Fully Coded, M Performance Spoiler and Black Grilles, 28% Tint, Charcoal Filter Delete, BMS Stage 1