Can't speak to the Jeep question.
I installed the Roadmaster base plate myself on my Honda Pilot. Roadmaster estimates 3 hours labor, so $400 is not totally out of line. It basically took me all day, as the whole nose assembly had to come off, and I basically just took a lot of time to ponder each step. Also, there were few screws that needed to be removed that Roadmaster didn't mention in their otherwise very complete instructions.