about the same as your mechanic is charging you because 1 it is a crossfire , 2 he most likely doesn't know very much about a crossfire,
3 he has you a customer who will pay, for something U can do yourself in less than 1/2 hour. swap out the bolts with the adj bolt., go under the car (with the car in the air remove the nut, jack up the control arm until the bolt turns freely,,,stop remove the bolt install the new one, make your adjustment rear needs to go to the right= arrow to the right,,,tighten the bolt .