How can consumers control medical costs when they cannot "shop around" because they do not know what the costs are?

We keep on hearing that by putting the onus of payment upon the consumer, he or she will be more aware of costs and will negotiate them more carefully.

In case those people have not noticed, not only do doctors, unlike MacDonalds, not post their procedures and prices, but in many cases are prohibited from discussing their prices by the contracts they have with health insurers. Even if they were to, how are laypeople to decide what tests, procedures and treatments are medically necessary when even doctors do not always agree. Then, even if you have discussed prices with a family practitioner, how are you to know what are the prices any specialist, to whom you may be referred, will charge. Lastly, if you are really ill will you sit down and negotiate prices before seeking treatment?

This seems to be a system which is designed to penalize the consumer in all ways.