I think the salient point is that in all jurisdictions, there are subsidies for locals, either through government or private industry, to make health care affordable. That those subsidies create perverse incentives is unsurprising. Since perverse incentives distort the market, they are not useful. Hence we cannot measure the true cost of health care by looking at what locals pay, because there isn't one single rate for a local (this includes free/fully subsidized). The true cost of the service is most clearly evident to those who do not qualify for any subsidies, it makes the most sense to measure that.

I mention medical tourism because it's a real thing. People do shop around globally to take advantage of medical systems where the cost-to-service ratio is beneficial to them, and in many cases, not all but many, those people are paying the true cost of delivering that service (this includes the flight cost).