Also, just having the ability to comparison shop tends to hold down prices, because firms know that you could go elsewhere if they're gouging you and that information tends to escape. It's like how when the wage-fixing cartel among Silicon Valley employers was discovered, everybody at Google got an immediate ~50% pay bump. You didn't need to actively interview at Facebook, because they knew you could and would rather that you not get that idea in your head.
Heck, even post facto, if you're in an emergency and you end up stuck at a hospital that charges $50K for a procedure, and then while recovering you find a nearby hospital that does it for $10K, you're not necessarily without options. It's not hard to go to the provider who actually gave you service and say "You know, they charge 20% what you do... what's the odds I can cause $40K's worth of stink in the local news if you don't cut my price down now?"
(You may want to consult with a lawyer friend a bit before making quite such a naked statement; that may constitute blackmail in your jurisdiction. But there will still be "ways" of phrasing things in your jurisdiction. Talking to a lawyer may not be all bad anyhow, whatever it is you have to say will sound more credible with some lawyer's letterhead on top. Hospitals hear a lot of amateur lawyers expound their novel legal theories every day.)
I'm not going to deny the relationship in that situation is still lopsided in the direction of the first hospital, but the situation is not necessarily 100% in their favor.
A mild correction: it was an effective 10% bump. Google used to have an individual and company multiplier to the bonus which could top out to 25%. The company had repeatedly hit the 25% company multiplier and had strong feedback that the employees preferred predictability in pay. So, they gave a 35% pay raise and phased out the company multiplier.
It also happened in October 2010, which I think was before the wage fixing was discovered (I know the dates because it was after I signed and before I started. Any time I tried to negotiate on salary they countered on stock because they knew salary was going to multiply by a third)
That is not an apples to apples comparison. A gentleman's agreement not to poach engineers with valuable skills is very different from companies charging people with services who are not able to say "no".
There is a massive information asymmetry between health care providers and consumers. Doctors take decades of training. Hell, medical billing by itself is a degree. Consumers will never be prepared to properly assess costs. Even if they could, it doesn't matter when you are hurt and can't refuse.
It's more like food sales at a hockey game. Anyone in the arena that wants to eat or drink has to buy what is being sold. As such, prices are hugely inflated, even though the nearby gas station is much cheaper.
