Ok so dumb question I always wanted to ask, about the arbitrary prices. Let's say I have no insurance and I collapse on the street, get rushed to the hospital and revived, after which they send me a bill for $10k. I didn't agree to any treatment; I didn't sign anything. What prevents me from saying that I won't pay it - not in "send it to collections" way, but in a "this is a fraudulent bill" way, like I don't owe anything at all? If the hospital can claim by fiat the price was $10k after the fact, how come I cannot claim by fiat the price was $100, or send the hospital a counter-bill for $9900 for having had the privilege of touching my chest? I mean, a car dealership cannot send me a bill after the fact for an extra $10k for driving off the lot?

(Semi-)serious question, actually. What would they do? There's no contract.

Even if I did sign something in an emergency, I can claim to not have been capable enough to reason about it, due to shock/mental issues given the emergency; and anyway does all this paperwork (that having good insurance I sign without reading) actually say "I agree to pay whatever you charge me"?