I would add that we used lacquer primers because that's all there was to use. The 2K primer/surfacers are better in every way. I'm a hobby painter, I do a couple of cars a year, and while it's hard to keep up with new chemistry, my results are far better, last far longer than the way I did things 20 years ago.
Materials DO cost more (it cost almost 800 to paint my '62 Impala) but I know that 10 years from now the car should look as good as it does right now. It sure wouldn't if it were painted with lacquer primers and acrylic enamel, my old favorites.