I had to have a shoulder replacement after a skiing accident, which involved three major surgeries in a month. Some of the numbers quoted on the bills were eye watering, with the whole thing "costing" over a million dollars. The daft thing is those numbers quoted on your bills are essentially meaningless and the start of a negotiation between your insurance provider and the health care provider, and the actual amount paid is somewhat less.
Add in the complexity around co-pays, deductibles and who pays what when, and it's a pretty complicated process. I reckon it still cost me personally over £100k, but a lot of that was due to my wife insisting that any bill we received was paid instantly rather than waiting for the final demand which apparently is often heavily reduced further.
The thing that got me was the lack of actual patient care, until you can stump up the cash. A real exchange after I'd been taken down the mountain in a blood wagon in agony:-
Nurse (standing over the other side of the room, and in a surly voice after hearing my UK accent):- "we dont take travel insurance so you'll need to present a valid credit card before we can go ahead"
Me:- "I actually live in the US, and so have health insurance"
Nurse (Now rushing over with a pair of scissors to cut off my T-shirt):- "Oh why didn't you say honey, let's see what we can do for you"
The change in their attitude when I confirmed they'd get their money was remarkable.