A growing number of patients are paying directly most, or all, of their medical bills these days. One problem they face: Finding out what health care services really cost before they make the decision to buy. Even though it accounts for one-sixth of the U.S. economy, health care is difficult to shop for in all but a small percentage of health care purchases. For the most part, no one ever sees a real price for health care services - not doctors, not patients, not employers, not employees. The reason patients never see the prices is because third-party payers (insurance companies, employers and government) negotiate with providers - leaving patients with a small co-pay under traditional insurance. And without real prices, there is no basis for third-party payers or anyone to negotiate the lowest possible prices. Recently, however, more and more employers are encouraging their employees to shop for health care the way they shop for groceries. To encourage that activity, employers are allowing their employees to manage more of their own health care dollars by means of a health savings account. The idea behind an HSA is a simple one: Instead of giving all of your health dollars to an insurance company or the government, you put some of those dollars into an account that you own and control. This reduces wasteful health care spending because individuals ... spending their own money often get the lowest prices, and they also can decide whether they really want to buy those services. A recent Rand Corp. study found that patients with HSA plans reduced medical spending by about 30 percent, without adversely affecting their health.