> They can't just raise the prices because people will bring their business to the competition.

Not necessarily. They're all under the same pressure. If they all provide similar services with little differentiation, the price will probably settle at a higher level to cover the fixed costs of 5 stores instead of 1.

> In my local market we literally got a scan for 2k where the hospital we'd usually go to wanted 10k.

You kind of get at it below, but I wonder if that's an effect of insurance negotiations (e.g. the hospital you usually "usually go" gave in to insurance discount demands in one area, but pushed back on scans pricing to get the revenue they need to operate).

I do think the totally fictitious nature of posted healthcare prices is a serious problem.