It began with a little black spot on Dan Callahan's lower lip. He didn't think it was anything to worry about. His doctor thought it was cancer.

The doctor was right.

It was neurotropic melanoma, a very rare — and very serious — type of skin cancer. Even after the little black spot was successfully removed six years ago, the cancer remained. And grew.

Last October, doctors at Barnes-Jewish Hospital began chemotherapy. They used a three-drug cocktail that includes Avastin, one of a new generation of anti-cancer drugs. It works by blocking the formation of new blood vessels that feed and nourish tumors. Until just a few years ago, that kind of treatment was the stuff of science fiction.

For patients battling advanced cancer, like Mr. Callahan, Avastin represents something as important as food or water: It is time in a vial.

It costs $13,686 per treatment. Mr. Callahan has received six so far. Total price: $82,116.

What's it worth? That's a much more difficult question.

About 10 miles up Illinois Route 13 east of Carbondale, Ill., — just above Crab Orchard Lake — lies a little town called Carterville. Mr. Callahan lives there with his wife, Stacy, and two daughters. Alexa, 18, is a student at the University of Illinois. Carly, 13, is in eighth grade.

You can buy a three-bedroom house in Carterville for about what Mr. Callahan's six infusions of Avastin cost. For about $100,000 — the price of a year's treatment — you can get a classic bungalow with a screened-in front porch, a long, shaded driveway and a two-bedroom cottage out back.

The Callahans both have good jobs and health insurance. Stacy works for a credit union. Dan is the head baseball coach at Southern Illinois University-Carbondale.

Their insurance paid for minor surgery to remove the little black spot from Mr. Callahan's lip. It paid for more extensive surgery in April, when doctors removed the right side of his jaw trying to stop the cancer's spread.

And it paid for yet another operation in September, when infection forced doctors to remove the prosthetic device they had implanted to replace his missing jaw.

But Mr. Callahan's insurance won't pay for Avastin.

The U.S. Food and Drug Administration approved Avastin in 2004 to treat advanced colon cancer. Since then, it has been cleared for breast and lung cancers. Doctors are free to prescribe it for other forms of cancer. It is being tried on 30 other cancers, including melanoma, but those uses technically are experimental.

Because many experimental treatments don't pan out, insurance companies in Illinois and most other states do not have to cover them. The major health care bills pending in Congress would not change that. For the first time, they would allow generic versions of so-called biologic drugs like Avastin, but only after 12 years on the market, twice as long as other drugs.

For thousands of Americans, including the Callahans, that means many newer cancer drugs are out of reach. "When they told me the insurance wouldn't cover it, I said we'll just pay for it ourselves," Mrs. Callahan recalled last week. "Then they told me how much it cost."

The Callahans scraped together about $27,000 from friends and family members — enough to cover the cost of two treatments. They got a grant from Washington University to pay for four more. They are appealing the insurance company denial, so far without success. The grant expires at the end of December. After that?

Mrs. Callahan paused. "We don't know what we'll do."

Despite the high prices and higher hopes, Avastin has been shown to extend cancer patients' lives by only a few months. Many patients and oncologists say it improves quality of life and shrinks tumors — or at least prevents them from growing. Mr. Callahan's doctor said it has slowed the progression of his tumor.

That is no small achievement for patients with advanced cancer. But stopping the progression of cancer is not the same as curing it. A study published in January followed 53 melanoma patients who received Avastin. After 18 months, 13 were alive.

The company that makes Avastin, Genentech, spent about $2.25 billion to develop it. It spends another $1 billion a year testing it on new cancers. Avastin has been a blockbuster success. It had $2.7 billion in sales in the United States last year and more than $3.5 billion worldwide.

Genentech says Avastin's price reflects its value. Another cancer drug, Erbitus, costs even more, and it has not been shown to extend life at all. In March, Swiss pharmaceutical giant Roche agreed to buy Genentech for $46.8 billion. Avastin is a big reason the company was sold for so much money.

Not everyone agrees that Avastin is worth the price. Experts in Britain recommended against making it widely available. A drug that costs as much as a house and extends life for just a few months isn't worth the money, they said.

Some people go to pieces when they find out they've got cancer. Mr. Callahan went to work.

He has coached the Salukis for 14 years. "I try to carry on like I'm going to be here next week and next month," he said. "I think about coaching in 2010, about going to my daughters' college graduations and their weddings."

His 2009 team finished with 24 wins and 28 losses. Coach Callahan was too sick to travel to away games. But he was in the dugout each time the Salukis took the field in Carbondale.

From the beginning, the Callahans have made it a point not to ask doctors about his prognosis. "We don't want to know it, and we don't want our kids to know it," Mrs. Callahan said. "We just wanted to live our lives as normally as possible, with no time line."

Coach Callahan thinks it is inherently unfair that patients can be denied treatment simply because of a drug's high price. It's like giving one team an extra at-bat.

But the game is not over. Even with two outs in the ninth inning, even with two strikes against you, there's hope. And a question: Who sets the price of victory?