There are a lot of ways in which medicine defies the market logic that dictates the supply of other goods. Paul Krugman identifies a rarely mentioned one:

Medical care is an area in which crucial decisions — life and death decisions — must be made; yet making those decisions intelligently requires a vast amount of specialized knowledge; and often those decisions must also be made under conditions in which the patient is incapacitated, under severe stress, or needs action immediately, with no time for discussion, let alone comparison shopping.
That’s why we have medical ethics. That’s why doctors have traditionally both been viewed as something special and been expected to behave according to higher standards than the average professional.

It's a basic point, but one that gets easily lost. Market logic assumes a certain level of adversarial tension between buyer and seller. That new television is worth up to $1000 to me, the seller could profit from any sale over $300. We both benefit from any purchase between $300 and $1000, and the seller's job is to push the sale up to the highest possible end of the range, while my job is to push it toward the lowest. The assumption that medical care can approximate this dynamic is bizarre. It only exists because of the American right's a priori belief in the primacy of markets.

Granted, we fall short of that ideal -- moreso than other advanced countries -- but the Republican vision of market-driven health care makes a mockery of the whole ethic.