The only concern you should have is that you will be ruined for other cars, even NA BMWs (Excluding M). My 2007 335i is my first BMW. When in for service my free loaner was usually at 328i. I could wait to get out of that and back into my car.
I do all of my own work now that it is out of warranty. It has 80K miles on it. Things I have done:
Cleaned intake valves (no parts) dealer would charge $850, indy around $400.
Alternator Pulley. Part was $80, 30 minutes in my garage
Battery. $219 for a battery from BMW, $80 for an indy shop to "register" it.
Tires. $850 for 4 mounted and balanced
Rear brakes: $365 for rear brake "kit special" from getbmwparts.com. Includes OE pads, rotors, sensor and paste.