$47,000 for my surgery!? *faints*

The hospital and everyone else bills full price. Then your insurance pays the agreed upon, contracted rate. You will be responsible for your portion, which for most insurances is a flat rate or a percentage of the contracted rate, not the billed amount, up to your maximum out of pocket.

I was self-pay because my insurance would not cover it but as others have covered the reason for the expense above. 

I had a microscopic surgery involving reattaching blood vessels - 6 years ago today actually - and that bill was INSANE. For good reason though. I had 3 top notch micro surgeons working on my for 5 hours. Maybe $150k? Completely worth it. I didn't have to pay that but I did have to pay 4k of it. Still worth it. Just like this surgery.

Counting all my approval tests, the total was around 95,000.  The heart test alone was $15,000.  The surgery itself, surgeon plus hospital stay, was $67,000 - I think he and the other surgeon only got something like maybe $2500 combined.  Crazy, when you think about it, since I was only a three day stay.  I paid about $2000 out of pocket for all the tests, doc visits, and surgery.

Medical care isn't standard in the US.  Some hospitals literally charge 50% less than other hospitals.

Did your insurance comp approve you? Or did you know you had to pay? My insurance said 100% coverage.  I just don't want any suprises.