My brother had the choice of having his broken wrist (the scaphoid) treated by surgery or by cast. He picked the cast because the total bill would be so much less. I'm not sure why the doctor would offer him the considerably more expensive surgery if the cheaper option was available.
Research has been done into the costs of treatments for broken scaphoids and, for the most part, costs vary considerably in either direction due to the patient's circumstances. For example, people who have surgery may end up paying more for the actual procedure, but if they have a job that they can't perform while wearing a cast, they will miss more work days, affecting productivity and sick leave. In this case, the surgery option comes out costing less overall. But, if the patients has a job where he or she can return to work with the cast, the amount of time lost would be significantly less, because of a much shorter sick leave period. In that case, the surgery would be more expensive than the casting.