While shopping for a heating oil company earlier this year, Steve Carpenter was quoted prices as high as $1.23 per gallon. But when he called Tri-Continental Oil, he said, he was given a tip: Call Buyers Up.

Buyers Up is a nonprofit consumer group that helps homeowners buy heating oil cooperatively as a way of lowering costs. It acts as a liaison, connecting consumers with participating oil companies that deliver oil at a price several cents per gallon below the market rate.

Last year, Buyers Up users saved an average of $220 in heating oil costs, a spokesman said.

Carpenter, a Northwest Washington resident, signed up right away, and he credits Tri-Continental for passing on the information. "I might not have found out about it any other way," he said.

Buyers Up was founded two years ago by consumer advocates Ralph Nader and Joan Claybrook, with Jason Adkins, then 24, as director. Since then, Buyers Up has enlisted nearly 5,000 consumers in Washington and its suburbs, and it has expanded to Baltimore.

The organization, which operates out of an office near Dupont Circle in the District with a staff of six, charges a membership fee of $15 for homes, $25 for nonprofit operations, and $35 for businesses. Low-income users pay reduced membership fees.

Antonio Fernandez of Fort Washington learned of the group when a Buyers Up representative spoke at a Riverbend Civic Association meeting. At the time, he was paying $1.25 per gallon; he switched to Buyers Up and a price of 96 cents per gallon.

"I've been very happy with them," Fernandez said of the cooperative group. "And they put out a newsletter, too, which is a very good service."

A check of eight area distributors this month showed oil prices ranging from $1.15 to $1.27 per gallon. At the time, the Buyers Up price was $1.05.

Energy consultant L.T. Via, who works with Tri-Continental, said that in the Washington market, a few large heating oil companies have kept steady customers for years.

To elbow into the market, a small, relatively new company like the minority-owned Tri-Continental firm must offer an appealing incentive, such as the Buyers Up price discount, Via said. The oil company trades a higher profit margin to gain customers, he said.