And even list prices themselves are typically starting points for negotiations when a provider is dealing with a large payor whereas an unwell individual (y'know, one who is about to spend a lot of money on healthcare) is not in a great position to bargain with her caregivers, and so is forced to negotiate after the fact, from an artificially inflated starting point, under the guise of bill reduction, or worse, debt relief.
Almost nothing actually works that way. Walmart doesn't stock exactly the same goods as Target. One of them may be closer to where you live than the other.
Which is why price isn't the only criteria. If the office closest to your home charges $250 and one which is fifty miles away charges $200, you can perfectly well choose to pay the extra $50 for the convenience.
The issue is that when the nearest office decides to charge $1000 and the one fifty miles away is still charging $200, that should maybe change the outcome. But not if you aren't aware of the price difference to begin with.
And this even applies to the beloved family doctor -- there is a limit to the amount of price gouging that a familiar face is worth.