Your theory only holds as long as every physician in the world colludes to jack up prices. Since they want to eat, they will eventually break down and help you as long as you can pay them. The price for their help, then, depends on how little the other physicians are willing to take to perform a service. Of course, this is only in the absence of government interference. In our current system, prices are generally set by government at arbitrary levels dictated by bureaucrats rather than anything to do with the procedure itself or how much physicians want to charge. This is the exact same thing nonlnear stated (much more eloquently).