I just called Kevin, and he explained everything to me. They only use Versatile products, which are professional grade. There is no industrial grade vs regular grade. It's one grade: professional grade. They would never ever use the Rust-Oleum product at Home Depot.
I made a mistake on pricing. They actually charge anywhere between $1450 and $1650 for 2-car garages. Some garages may have a little closet space on the side, etc, and would command a higher price. I didn't know that several months ago when they did my garage because the home builder gave me the epoxy for free (flooring contractors left stains on my garage concrete that couldn't be removed).
One final correction to my earlier post. Earlier, I had said that they put primer on the vertical lip so the epoxy and sealer (polyaspartic or polyurethane) won't peel off, which is incorrect. Rather, they use the primer to smooth out the tiny bumps on the vertical lip so the epoxy and sealer will be nice and smooth. You may have noticed that the vertical lip portions of your garage feel different from the rest of the garage concrete. That's because home builders will use a polymer modified concrete to shape and "finish" the vertical lip. This material will have a ton of tiny bumps, and because it's porous, the epoxy will soak into it instead of just grab the surface, thus preventing a smooth epoxy finish. The primer solves this issue.