I think you got a good price on the brake job.
I usually feel like rotors should warrant replacement about every two or three brake pad replacement cycles...you would have been due for one eventually, but probably not at 86K. I can't see your old rotors from here, so I don't know if there was any premature or excessive wear that might have required replacement when it did.
As PEH said, the rear ones probably didn't need replacement. As it is, rear brake pads last about three times as long as the front ones...I've replaced my rear pads on my 300E for the first time at 95K, but the fronts got replaced then, and again at 110K. I'll swap the rotors at the next replacement cycle.
Brake work on your car is relatively simple, so stay with the forum and learn how to do them yourself. Parts are inexpensive, and you can do the entire job in a few hours and save $$$.
In the meantime, hose off the area that the brake fluid spilled...use a gentle spray, or you'll wind up splattering the brake fluid droplets on other parts of the engine...
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car