Question on R. Brake replacement

My wifes '05 LE needs new rear brakes. I planned on swapping the rotors as well. I read the guide on here for it and was caught off guard by all the flushing and such. I drive a Dodge Intrepid and I simply change the pads, rotors and bleed the lines. The way it sounds I can't simply do it this was, correct? Do you have to flush the system or can I simply do as I planned? I don't know if the rotors need replaced but I always see it as a small cost to ensure all is well. What is the ball park figure a dealer will charge for rear brake job? Thanks.

Somewhere in PA.