I havent checked pricing lately but turning rotors should be about $10 ea. or less. It's a pretty simple process. I dont know that I would change the rotors unless you need new rotors or you just want to go with the slotted/drilled rotors.

I am getting ready to do my brakes and am changing to slotted fronts and drilled&slotted rears with DiscItalia Titanium Kevlar pads and Goodridge stainless steel brake lines. My front rotors look a little grooved and the right front had a defined groove in it. That's enough excuse for me to do the upgrade.

MikeR