Well, in some sense that's true of most businesses, right? Some customer interactions take up more overhead and resources than others. The trick is to aggregate that uncertainty over your customer base and come up with a price that incorporates your expected average costs. There are a lot of businesses that do this successfully because they have to in order to participate in the market. The reason health care providers don't seems to me because that are isolated from competition by heavy regulation. (I'm not saying the regulation in the health care space is necessarily a bad thing on balance, but it means that change can only come through additional regulation rather than depending on hamstrung market forces.)