They bill you after the fact, after they know what they did and what insurance paid for. At that point it is easy. But before the operation, nobody knows what they will find or what insurance will decide.

Your example is extraordinary and could be specifically excluded.

On what evidence do you conclude that it is extraordinary?

All evidence that I have, including my conversation last night with a retired head nurse, is that confusion and uncertainty about what will be covered by insurance and what negotiated limits there might be on what can be charged are more the rule than the exception. And if my impression is correct, then what you want is impossible. Because before the fact, nobody really knows.