If I was a billionaire I'd build a giant rig off the coast just outside of the US's territorial waters. A giant clinic & hospital rig exempt from US Federal medical and insurance regulations and US personal injury torte law. I'd staff it with the best competent doctors and supporting staff from around the world. Some of the same medical pros that are fed up with "the game". I'd supply all the top-shelf medicines and medical equipment from vendors outside of the US like the ones from Canada and Mexico that give you the same product at 1/4 the US rip-off costs. People would sign away their rights to sue for malpractice. The form of payment would be cash or credit card only. The money saved in red-tape, regulation paperwork, and malpractice insurance would more than make up for the lower costs paid by the patients.
..."Hello Mr. Jones, your appendectomy will cost $2300.00 out-the-door. When would you like to set the surgery date? And your wife's $600.00 bunion surgery can happen at the same time to save you money on the helicopter taxi."
Now that I think of it have them in several spots along the US/Mexican border with regular flights to their adjacent airstrips next to the facility.