Use media tion, arbitration, and small claims court. When possible have all tests done in advance on an outpatient basis. Keep copies of the results. Treatment in a doctor's office is the least expensive. It's more in an outpatient center, and most in the outpatient dept. of a hospital.
Some immigrant doctors charge less.
Don't use inpatient services when outpatient ones are as good. Use a community hospital over a teaching hospital. Don't go into a hospital from Friday afternoon through Sunday, unless it's an emergency. Don't go to a specialist until you need one. Get 2nd opinions before surgery.