I can think of a few ideas:

* you can't get paid by insurance unless you have payment authorization from the patient on an estimate that is within 30% of the actual price (exceptions for emergency care).

* a requirement that all provider participate in an digital marketplace where patents and providers can get immediate quotes for labs/procedures and you get a list of local options+prices.

* anti-trust break up of healthcare cartels

* some price cap like 200% of medicare negotiated rates as a backstop for these really crazy outlier bills.