You are right. But even if powder were free, it would still be bad.
Powder coat has no business on the exterior finish of an automobile.
@Yeller I also had a friend in the powder business. He worked in a shop, and powder coated everything in his spare time. And I do mean everything.
But there are two problems with powder. First, it bakes at high temperature. So all of the filler, sealer, deadener, and adhesives get baked off. Second, it has no capillary effect. So any seam or overlapping panel will not get the paint "sucked-in."
This results in catastrophic rust promotion in the seam overlap areas. You can't win. You can't seam seal over the powder, and the seam seal is baked off during powder. All that happens is the seam discolors and rusts in about 2 years. The white hardtop was beautiful, except where it discolored in the seams and gutters. He had the doors in powder as well. Looked unbelievably horrid, because he didn't have filler. It was so bad that he abandoned the project and sold it to me.
I will admit that powder made some excellent primer. But you need a liquid to fill in the overlaps and seams. The VW Beetle had it right. If I could dip my Bronco into a vat of paint, I would.