Ralph Nader has given up raisins, Esther Peterson is eating more beans and Karl Hess is trying to make it without money.

Other members of Washington's public-interest community - people who pride themselves on practicing what they preach - are fighting inflation by cutting their kids' hair themselves, wearing 10-year-old suits and giving up cars.

Consumer advocate Nader said he renounced raisins when they went "sky high", from $1,10 a pound last year to $2 a pound now, due to last fall's heavy rains in California.

A self-proclaimed "ground-zero spender." Nader said he always shops at sales, doesn't buy much meat and has canceled one of his several office subscriptions to The Washington Post.

White House consumer advocate Esther Peterson said she's eating more vegetarian meals and is "trying more soups and stews based on dried beans and lentils." Peterson has cut down on portion size to reduce waste and buys supermarket house brands whenever possible.

A pioneer of unit pricing when she was consumer-affairs adviser for Giant Food, Peterson said she always compares prics and does her own grocery shopping so she can chat with other shoppers.

Karl Hess, former Republican ideolgue turned tax resister, author and welder moved in 1976 from Adams Morgan to rural West Virginia where he barters his welding services for everything from food to gravel.

"Bartering is a good way to trade skills," said Hess, who did some welding work for his dentist in exchange for lessons in "how not to have dental problems."

"In a rural community, people are cooperative and there's good deal of sharing," said Hess, who lives in a 75-percent energy-efficient house he built himself for $9,000. "I've rediscovered public libraries. I used to spend a good deal of cash on books - and I stay put more."

Riding the Metroliner ( $28 one-way) rather than flying the air shuttle ( $42 one-way to New York is one way Federal Trade Commission chairman Michael Pertschuk saves money.

"We installed a great big attic fan so we wouldn't have to use our air-conditioner so much," Pertschuk said. "And we're seriously thinking of getting rid of our second family car."

"I think a car is an unnecessary luxury when you live in the city." said Consumer Federation of America president Kathleen O'Reilly. "The insurance, gas and parking, puls the grief of taking it in and out of the shop, isn't worth it." O'Reilly said she occasionally rents a budget-rate car for weekend trips.

Edith Barksdale Sloan has cut down on visiting out-of-town relatives and takes the subway to her job as vice-chairman of the Consumer Products Safety Commission.

"We haunt the museums and look for weekend freebies that we can take the children to," said Sloan, who with her husband and two sons raises strawberries, cantaloupes, tomatoes, bush beans, broccoli and Brussels sprouts in a home garden.

"And I haven't bought any new clothes all spring. I looked at the prices and at the new styles and decided to buy some accessories instead."

National Consumer League head Sandra Willett said by working 12 to 14 hours a day she saves cash: She has no time to buy anything. "I find I'm cooking and recooking foods to use up all leftovers" (often in homemade soup).

Willett also has cut down on magazines by about 75 percent, retaining subscriptions to Consumer Reports, Ms and Time. She cut out all theater subscriptions except "the cheapest seats in the house at Arena Stage," and is making do with clothes she's accumulated over the past 15 years.

"Economists are considered tightwads by most people," said Department of Agriculture economist Dawson Ahalt, admitting he's been a penny pincher for years. "I drive old cars which get good mileage with regular gas, and I try to repair them myself."

Ahalt's usual lunch of soup and cottage cheese in the department cafeteria costs less than $1.50, and he rides the Metro rather than cabs across town. "Also, I have on a pair of shoes over 10 years old that I've gotten resoled and reheeled when necessary."

"My kids used to tease me about driving 'The Old Falon'" Ahalt said. "But I think if parents set an example of getting away from materialism, everyone will be better off." CAPTION: Pictures 1, 2, 3, 4, 5 and 6, From top left, clockwise, Michael Pertschuk, Ralph Nader, Edith Barksdale Sloan, Esther Peterson, Karl Hess and Sandra Willett.