>We should absolutely have legislation that mandates that public investment in drugs is returned to the public in kind
I don't think this more of a policy problem than a legislation policy. The US government can simply stop giving away free money at any point it wants.
>it’s hand-waiving to pretend that the people on the receiving end of high drug prices should’ve negotiated better prices for themselves
I think you may have missed the point I was making in my last post. I am not saying that drug consumers should negotiate better prices (although this is how prices are controlled in every other first world country). What I was saying that the US government intentionally gives away money with no strings attached for R&D. The explicit purpose of this funding is to help companies make products and profit. If the outcome you want is different, we need to look at different terms or a different investment vehicles.
One simple option would be requiring recipients of federal research grants to publish in open journals and open source their patents. the down side, is that this may reduce the chances of them being developed at all.
In addition to the US government, there are similar challenges for non-profits and charities, which often give money to large drug developers, or sell internally developed drugs to the for profit sector. You might find this paper interesting [1] as well as the history of ivacaftor.
[1] https://www.tandfonline.com/doi/full/10.1080/20016689.2018.1...