The parts are $600 front and back for oem rotor and pads. $1400 means the labor was like $800. That's about 6+ hours labor at $120/hr.
It does not take 6 hours to do rotors and pads for the dealer. They have a lift and air tools. 3 hours at most for rookies, 2 hours for veteran mechanics who've done it 100 times already.
In addition, those price for parts is retail. So the dealer gets those parts at wholesale prices and passes on the difference in cost between retail and wholesale to you. As a result, the dealer not only made exorbitant money in labor but some in parts as well.
This was in my opinion at ripoff. Buy the parts and take it to an independent shop next time.
2009 335i 6MT - M-Sport - All stock