While I agree with some of what you say, I take issue with the following:
> You're never going to say that "ah this treatment is a bit overpriced; I think I'll get more value for my money if I'll just die instead".
No one is rationally arguing this. The free-market point-of-view is that multiple providers will offer you treatment, and you can select, based on quality, price, provider's reputation etc. etc. what best fits your needs.
Over and over in this debate I see this fallacy that a free-market system says "You pay this price or you die." If a procedure can be made cheaper or more effective, a variety of providers is going to scramble to provide it.
The difficulty we face in the U.S. is that there is no real competition in healthcare. As others have pointed out, the people making the purchasing decisions are not the people with a vested interest in the affordability and quality of healthcare, and price/quality signals are obscure at best, and typically hidden altogether.
You, as a consumer, can't make rational healthcare decisions when your insurance is selected by your employer, your doctor is chosen by your insurer, and your treatment is chosen with an eye toward liability rather than effectiveness.