"Health insurance companies are rapidly adopting a new pricing system for very expensive drugs, asking patients to pay hundreds and even thousands of dollars for prescriptions for medications that may save their lives or slow the progress of serious diseases.
With the new pricing system, insurers abandoned the traditional arrangement that has patients pay a fixed amount, like $10, $20 or $30 for a prescription, no matter what the drug’s actual cost. Instead, they are charging patients a percentage of the cost of certain high-priced drugs, usually 20 to 33 percent, which can amount to thousands of dollars a month.
The system means that the burden of expensive health care can now affect insured people, too. Insurers say the new system keeps everyone’s premiums down at a time when some of the most innovative and promising new treatments for conditions like cancer and rheumatoid arthritis and multiple sclerosis can cost $100,000 and more a year.
But the result is that patients may have to spend more for a drug than they pay for their mortgages, more, in some cases, than their monthly incomes...."
http://www.nytimes.com/2008/04/14/us/14drug.html?no_interstitial