All very good comments
My own experience, I never media blast cars, as said previously, silica residue, sand residue, heat warp and buckle.
Garnet is used for industrial use and should never be anywhere near a car, soda is good if you must, bead blasting generates too much heat, sand under too much pressure has the same effect
You pay for what you get? Ive seen some real crap from some so called pro's, who run for cover when you take a good look at their mess
For what its worth, I always acid dip my shells and panels and then epoxy prime the bare metal
An hourly rate is the only way to go, and keep the jockeys out of your workshop!!!!!
Cheers