Tell them they are full of it and must not want your money
My friend works at a Chevy dealer service dept. and we aligned my car this past Friday. I have H&R Sport springs w/ Koni shocks (extra 1/2" drop in back). I do not have a camber kit. He hooked up the sensors to all the wheels, adjusted the rear toe, then adjusted the front toe to the rear, so all 4 wheels were in spec. for toe-in. My camber readings were:
front -2.1/-2.3 L/R
rear -1.7/-2.1 L/R
I have been on this suspension for 12K miles now (had an alignment previously after first installing suspension), and with rotating tires every 4K-5K miles, my tire tread is still perfectly even all the way across, with NO signs of uneven wear.
My right front tire was showing slight signs of scrubbing on the edges of the treadblocks, which is why I wanted to get my car re-aligned, and sure enough my toe-in was off just slightly.