When Steven Carpenter of Park Road NW shopped for a heating oil company earlier this year, he was quoted prices as high as $1.23 per gallon. When he called Tri-Continental Oil in Northeast Washington, he received not a price but a tip: call Buyers Up.

Carpenter now pays $1.05 per gallon for fuel oil and is among 5,000 Washington area consumers who have joined Buyers Up, a nonprofit buying service organized by two of the nation's leading consumer advocates -- Ralph Nader and Joan Claybrook. Carpenter credits Tri-Continental with passing on a "very nice" bit of information. "I might not have found out about it any other way," he said.

Buyers Up, founded two years ago, provides less expensive heating oil to consumers through group buying. The company operates from a small, second-story office just off Dupont Circle, with a staff of six, a computer and endless volumes of oil industry publications.

Buyers Up owns no oil, no trucks; it makes no deliveries. It is a middleman, bringing a large group of consumers to oil companies that are willing to deliver oil at a price below the market rate. Last year, Buyers Up customers saved an average of $220 in heating oil costs, said Jason Adkins, the company's director and one of the founders.

The service, now available throughout the Washington area, is open to any heating oil consumer. The membership price ranges from $15 for homes to $35 for profit-making businesses. Low-income users pay only a $5 membership fee.

A week ago eight area fuel oil distributors had prices ranging from $1.15 to $1.27 for a gallon of heating oil, according to a telephone survey. At that time, the Buyers Up price was $1.05.

Buyers Up also helps small fuel companies getcustomers -- and thereby a toehold in the Washington market, which is dominated by a few large heating oil companies.

Small new companies such as Tri-Continental are willing to trade higher prices for a larger, stable supply of customers paying lower prices. As "a new, struggling, minority-owned company trying to get started in the business, Tri-Continental is perfectly willing to sell at a reduced price," said L.T. (Pete) Via, an energy business consultant who works with the company.

As a nonprofit service, Buyers Up operates on a limited budget that precludes a sophisticated advertising campaign. Staff members spread the word by speaking at churches, Advisory Neighborhood Commissions and union meetings, and by going door-to-door.

The door-to-door campaign introduced Barbara Bankoff to Buyers Up. Bankoff, of Yuma Street NW, said she was skeptical at first, "but I read the terms of agreement very carefully and I was convinced of the organization's viability," she said.

Audrey Walker of 13th Street NE heard about Buyers Up from a TV show two years ago. She called immediately to sign up and has since encouraged friends to join the buying service. She said she has "never kept track," of savings, but "you could see the price is lower."

Vivian Van Horne of Massachusetts Avenue SE said she saved about $100 last year with Buyers Up. "Oil is oil, and there is nothing glamorous about one kind over another," she said.

Antonio Fernandez of Fort Washington learned of the group when a Buyers Up representative spoke at a Riverbend Civic Association meeting last year. At the time, Fernandez was paying $1.25 per gallon for oil from a company that he had used for years.

He switched to Buyers Up, which was offering a price of 96 cents per gallon. "I've been very happy with them," Fernandez said. "And they put out a newsletter, too, which is a very good service."

The newsletter includes an "Ask Buyers Up" column for energy-related questions, and articles on topics ranging from heat loss through fireplaces to an explanation of high oil prices in the midst of a world glut.

Buyers Up also offers its customers energy conservation services such as energy audits, which survey homes to reveal heat lost through doors, windows and furnaces.

The audit, some demonstrations and instructions on energy improvements are free to Buyers Up customers, on the condition that they follow up on the recommendations -- such as fresh caulk around windows, weatherstripping on doors and effective dampers on chimneys -- or pay a $25 fee, Adkins said.

Adkins has tried to get the D.C. Energy Office to include information about Buyers Up on the "Coldbusters Hotline," which tells callers with heating problems about city-sponsored assistance. Director Chuck Clinton said, "Generally we support the idea of cooperative buying to save heating costs. We would be more than happy to instruct our operators to mention Buyers Up to callers."