[pessimizer]

Yeah, I don't get it. If you have infinite resources, and you absolutely know the doctor is competent (a question omitted here that would make this more interesting) just tie the doctor's fate to yours.

I don't know if overpaying will work, because the marginal value of money goes down the more you have. Once your doctor is rich enough, he won't be overly concerned if you die and the checks stop coming in.

The real answer is the action-movie/not-that-uncommon-in-reality answer: Credibly promise to shoot the doctor if you die, or to shoot the doctor's family members.