I think you actually have this kind of backwards. For example, when I broke my toe last year I had to wear a boot for 6 weeks. I didn't really have a choice but to let my Dr give me one, given my inability to walk without crutches or a plaster cast otherwise. I received a bill from them for $384 a couple weeks later. It was the first bill I disputed with my insurance company, using the fact that I could buy the identical product on Amazon (and a number of other online retailers) for <$80. Aetna was just "tough luck" and paid ~$200 of it, leaving me to pay the other ~$200. Things like this happening are just plain stupid.