It's because in healthcare, the vendor never knows if or when they will be paid, and how much it will cost to get paid, so the strategy is to charge as much as possible and just hope for the best. That means people who are dead broke get their care for free since they have nothing to pay with, insurance companies and the government strong arm the vendor into discounts since they buy in volume, and the person that gets screwed is the little guy who makes enough money to not be poor, but not enough money to have gold plated insurance but he also can't fight the hospital.