I have been waiting for doctors and other medical staff, especially in ERs, to stand up about the insane over-charging that takes place. Everyone seems to have a story, but in mine before I agreed to anything I asked how much it would be. I was given an estimate of around $1,200 for a scan, decided to proceed because I knew I had $1,800 in my HSA. Turned out they charged me almost $4,000 and I ended up in collections. I would have never, ever agreed to the scan if they had been honest.
A month or so after an emergency visit to the hospital, I started getting random bills in the mail ranging in $50-$100 amounts. I went back to the hospital and asked them what the total was so I could just pay them the full amount right there, which was only about $1000. They simply wouldn't tell me. They told me to wait for all the bills. As I paid them off, there was no indication of whether I had completed all the payments.
Guess I missed one, as I also ended up in collections a year later for $50. My credit score was harmed instead of theirs.
Last time I got a mortgage it turned out I had a couple of dings on my credit record because of unpaid medical bills (totaling a few hundred dollars) that I had missed and that had gone to collections. The banker processing my mortgage application said "It's not a problem. Everybody in America has unpaid medical bills. We ignore those."
Also you can usually mail a check with a short letter explaining you are paying the estimated cost and caching the check is the same as honoring that estimate.