>> He billed my insurance just under $300 for an exam that took under 5 minutes.
This is really common in health care.
I injured my shoulder during hockey and went to the ER. The ER nurse told me to go to a specialty clinic that had offices all over town. Told me to bring a book since they do walk ins and it will be a while before I was seen. Brought a book and checked in. Three hours later, they took me back. I waited for about ten minutes and then the doctor came in.
Same thing. He asked me to raise my arm in several different directions and then announced, "Keep taking your anti-inflams, be about 6-8 weeks before it heals" and walks out. On his way out he kind of hollered back, "And do some stretching so you don't lose your range of motion!"
My insurance got billed $600 for a 2 min appointment.