I don’t know what vehicle your referring to, but, yes, rotor service typically costs more than new pads. I can buy semi-metallic pads for my truck at $25 a set. It will cost me $15-$20 per rotor to turn them. It will cost me $75. per rotor to replace them.
However, turning the rotors ARE important. The rotors develop a wear pattern with the old pads. Just slapping new pads on means they need to conform to the old wear pattern, which takes longer and forces the pads to wear faster. And the odds of bad brake behavior, like chattering, noise, and warpage increase. In my shop, we turn or replace rotors with every brake job to reset the brake wear pattern and greatly reduce the odds of bad brake behavior. We don’t want to have to re-do jobs by cutting corners.