Out of curiosity, I looked up approximate costs of my last surgery, in countries with different health systems. In several cases the operation was not covered by health insurance, and it was very variable even within the same country.
In Australia, the cost could have been as much as $6000. In the US, people were charged anything from $4000 up to $42000, depending on the type of insurance they had.
The saddest thing was the number of people who were living with this condition, and the associated complications, as their insurance did not cover it at all and they had no means of paying. Other patients spoke of having to borrow on multiple credit cards or from family and friends, going in to huge debt just to be healthy.
Though this was a relatively simple operation, which didn't even require an overnight stay in hospital, if it wasn't for the NHS I would not have been able to afford to have it done. Now imagine this was more complex, or life-threatening?