Ok, for replacing the rear pads and rotors, you are looking at 2.4 hours labor, and depending up brand and quality of parts, you should be looking at $60-90 for the pads, and $60-110 per rotor.
So parts will be $180 - $310 and 2.4 hrs labor. If labor is $100 per hour(high side for an independent shop) would be looking at $240 labor, but probable more like $80 per hour so labor would be $190
Parts and labor on low side will ber $370 and high side $550. Anything in between those prices is a fair quote