I was a member of a very large public sector health plan that was extremely aggressive about negotiations, to the point that for awhile any maintenance medication had to be shipped from Canada. They get good prices, but not that good -- iirc my blood pressure medication total cost was 10-15% less than the shitty small business HMO that I had previously.

Generally speaking, the US government demands most favored pricing and gets it. No way we would pay more than France.

Europe does better because they have the ability to prevent sale of a drug and the drug company can just raise the price in the US. If the US gets in the game, I would expect European prices to spike, especially in smaller countries.