No, I have seen that. I have even called and asked why I was charged $15 for a towel to wipe the ultrasound gel off my wife's belly, when it was just paper towel, and if I knew it was going to cost me $15 I would have done it myself. And I was told to ignore it.
But that seems irrelevant to my point. If you worked at an insurance company (not just health), and were tasked with contracting vendors (such as doctors or mechanics or construction), would you not want to stipulate that your vendor is giving you the lowest price publicly available from that vendor to avoid paying more than necessary, which would then allow you to offer your customers lower insurance premiums and compete with other insurance companies?