This short BusinessWeek Online story does a good job of summarizing the reasons why America’s health care finance system hinders the decline in prices in health care that Americans have enjoyed in many other sectors of the economy, most notably retail sales (ala the Wal-Mart reference). One big reason noted:

Sometimes, however, Americans use more care because they think it’s free, or almost free. And that’s one big reason why health care hasn’t become Wal-Mart-ized. When you buy that DVD player, you whip out your credit card and pay with your own money. That makes you want to comparison shop for the best deal. But when it comes to buying drugs, consumers have little incentive to shop around. If you have good insurance, you’re going to pay the same $10 or $15 whether you need the most expensive drugs or not.
A recent study that looked at drugs used to treat arthritis pain provides some insight. Arthritis sufferers can buy relatively inexpensive over-the-counter treatments, such as Motrin or similar generics, or much more costly prescription medications called cox-2 inhibitors, such as Celebrex or Vioxx. Both kinds provide equal pain relief, but the cox-2 drugs may reduce the chances of stomach bleeding or ulcers.
The study concluded that people with good drug insurance were twice as likely to get the more expensive drugs than those without insurance, whether they were at risk for bleeding or not. If someone else — the insurance company — is paying, price doesn’t matter.

Hat tip to the Mises Economics Blog for the line to this article.