Yes, in this case, the ultimate issue is 'why can't I access an oxygen mask at something approaching market cost?'

In the US, that answer is 'because a legion of insurance middlemen want their cut for work they aren't even doing.'

If you're going to say "well it wouldn't cost $13k in the NHS version" then we're closing in on the actual issue which isn't who foots the bill but what the bill is which can be addressed in ways besides "nationalize everything."

Correct.

It's not the case in the UK that 'everything' is nationalized. We have private medical providers (some of which also provide services to the NHS) and for some things, I would recommend that over the NHS even for the poor - I am never waiting six months save to £350 on an ultrasound ever again.

My personal opinion is that there is not enough availability of private care in the UK (because it has to compete with most people defaulting the NHS), and not enough availability of public care in the US. The politicians of both countries seem to agree with me on that, as they've made attempts to push things toward that middle ground in the last decade.