Not to power level, but my eyes were opened when my first child was born. There was confusion at the hospital as to how my child was covered so they sent me a bill. $24k, but they would take $18.5k cash with a number to call to negotiate that. My health insurance paid $36k. Yes, you all read that correctly.
We all think internet grifters are bad. They have nothing on the health insurance industry.
Hospitals will routinely (and eagerly) accept cash offers of 20-30% of the original bill, the moment you offer, no haggling or questions asked, with "account in good standing, amount owed $0, thanks for your business, come back anytime!" once the payment clears. Not even kidding.
It's the world's worst-kept secret that literally every medical entity overbills insurance companies for everything they provide and do, hoping the insurance company will eventually pay some small fraction of that amount, sometimes as little as 10% of what they bill depending on the service and entities involved.
When they hand over that first inflated bill, they don't expect you to pay it. It's their first volley in the bullshit ping-pong game they play with insurance companies. The moment you start waving cash, they perk right up (because your payment clears
today, whereas the insurance payment (if it comes at all) will take months). You may not get as low a discount as what the insurance company would pay (which is bullshit), but they'll bend over backwards to accommodate you if it means getting some cash from you today. Discounts, payment plans, assistance getting financial help from other sources (i.e. charities), you name it. All of that is cheaper, easier and faster than dealing with the insurance companies. Pays better, too.