We pay a lot for healthcare, but that money is not spent on healthcare.
It is an important distinction. For example, about 33% of healthcare dollars go to paying “claims proceesing” people at your insurance company and your doctors office to haggle with each other and produce duplicate paperwork.
If the low end of your estimate (5x) is the correct multiplier, the money that goes to claims processing would be enough to pay for universal healthcare in pretty much any other first world country.
Other things, like absurdly high drug prices, also are not healthcare spending. 90+% of drug discovery research money is spent at universities, and not by pharmaceutical companies. Also, those companies pay more for prescription drug advertising than for drug research.