The answer is almost certainly large scale fraud by organized criminal groups, but investigating and publicizing this is, currently, extremely politically inconvenient.
Went to clinic for fractured arm. Was given a sling, told it was included with the visit, verbally by the staff.
Later get a bill for nearly $500 for the sling that costs $50 if you get it outside of the clinic. Was told they think they accidentally billed me the insurance price. I can understand "convenience" being baked into the price but not at a 10x markup. The more I talked with the clinic trying to get them to fix it, the more it sounded like they had a partnership with the stupid sling company where they put slings on people and bill the insurance 10x the cost of the sling.