I got a bill from the trauma center hospital for something like $500. Based on what I've been conditioned to expect from the U.S. health care system that seemed pretty reasonable. Then I got a bill from Northwell Health where I recieved no care for more than $800! Around that same time the NY Times came out with a piece about Northwell overcharging (https://www.nytimes.com/2021/03/30/upshot/covid-test-fees-le...). It took me months of badgering both my insurance company and Northwell to stop sending me payment delinquency notices.
Now, more than a year and a half later, they started sending me bills for that $800 again! So I'm very excited to see this kind of open source approach at this problem.