Sure, but you also can’t guarantee that without insurance either.
Are you going to ask the ambulance to take you to a different hospital when the first one gives you their rate schedule for heart attack interventions?
I haven't used it and don't know how good it actually is, but I have browsed for insurance on the Healthcare Marketplace (aka Obamacare) and they set out some pretty strict levels of coverage, services, deductibles, etc. in a standardized way.
But most people don't participate in that market because it would be silly to when your employer gives you a group buy rate plus an extra employer-paid subsidy to incentivize you to be part of the group buy.
Are you going to ask the ambulance to take you to a different hospital when the first one gives you their rate schedule for heart attack interventions?