Apart from the obvious cases of fraud (which seem to be concentrated on govt programs) and reducing some of the monopolies (including things that should be OTC), it's not clear that they're significantly overpaid. (Yes, I know about the "marketing" argument, but that includes free drugs to poor people and it's how folks find out that what they have is treatable. I see both as good. And allowing old people to have sex is a good thing.)
We want people buying Cadillacs (and Mercedes) because that's how we get good things in Toyotas.
A lot of US health spending is triggered by things that are outside the healthcare system. The only thing that the healthcare system can do is refuse coverage, and no one will admit to that.