(A) The patient knows what needs to be done (rarely the case)
(B) The care is not emergent (i.e., the patient can wait)
(C) The prices as quoted are accurate, complete, and don't change rapidly or dramatically
If any of those isn't true, then "shopping" for medical care is unrealistic and an unreasonable expectation for the vast majority of people to do. And I'm not talking about going to a minute-clinic at the drugstore for someone to confirm that you have the flu and here's a prescription. I'm talking serious medical issues.
My wife is a physician (double board-certified at one point; she knows her medicine). I have a PhD in business with faculty appointments at two different medical centers, so I have a decent understanding of how hospitals work. Between the two of us, we can't "shop" for medical care for the vast majority of our care needs because each instance violates one or more of the conditions listed above.
Oops, our son needs stitches...no time to shop around, he needs care now.
My foot is bothering me, but I don't know what's wrong. There are lots of different approaches I could take to getting it diagnosed and treated. Am I supposed to price out all the different possible care scenarios, factoring in all the "what if" situations that could occur?
Or, like the couple in the story, we try to use a cost estimator and are surprised when the actual bill has tons of charges that weren't part of the estimate (because that's how medicine works in the US).
So if my wife and I can't "shop" for healthcare, given our experience and training, it's wholly unreasonable to expect the vast majority of people who need care in the vast majority of serious health situations to be able to do so. And that renders this whole "informed consumer" argument largely moot. Instead of having healthcare providers compete on cost, a single-payer system would ensure that care is provided and care is compensated, without putting additional burden on the patient (who already has enough to deal with, what being sick and all).