High-performing principals could essentially opt out of the bureaucratic system, saving them thousands of dollars and putting pressure on central administration to downsize, under an idea being considered by the city Department of Education.

New York City public school principals now pay for the services of groups called school support organizations, which offer aid in such areas as budget management, teacher training, and curriculum ideas. Under the new proposal, one support organization, the empowerment network, would introduce two kinds of membership at two different prices. A regular membership would buy conventional services at the current price, $29,500; a new associate membership would buy a scaled-down set of services — relying much less on central bureaucrats — at a discounted price, $12,000.

If it goes into effect this July, the proposal would be on a trial basis, with only high-performing schools having the option of becoming associate members. The empowerment network’s CEO, Eric Nadelstern, said he expects just 25 schools would join.

However, if scaled up, the idea could lead to a radical downsizing of the role of central administration bureaucrats in a school’s daily life — and could also slim down taxpayer budgets.

“What we’re saying now is, the determining factor is the schools themselves have to agree that the service we provide is one that they require,” Mr. Nadelstern. “That’s a revolution.”

The idea is one of dozens swirling inside the Department of Education as the city, facing declining tax revenue projections as the economy tumbles, presents it with escalating budget cut estimates for next year. The department already slashed $180 million this year, and the latest projections are for $539 million more in cuts by 2009.

Chancellor Joel Klein has not yet decided on Mr. Nadelstern’s proposal, though several top aides to Mr. Klein, including deputy chancellors Christopher Cerf and Kathleen Grimm, spoke positively of it yesterday. However, he has asked all school support organizations to consider lowering their fees, education officials said.

Other ideas include changing the way teachers grade tests — a new way of grading that pays teachers to grade them after school has escalated costs by more than $30 million — and ending a relationship with an outside consultant that conducts quality reviews of schools, Cambridge Education Associates, in favor of hiring internal staffers to conduct the reviews.

“Everything is on the table,” Ms. Grimm, who oversees the education budget, said yesterday, after briefing reporters at City Hall.

“We are looking at every aspect, and we will drill down in every pocket,” she said.

She spoke over the sound of music drifting in from a protest just outside that attracted thousands of people, including members of the teachers union, the principals union, and parents and children at public schools.

The theme of the rally was a demand that state and city officials “Keep The Promise,” referring to a lawsuit charging the city schools were inequitably funded, which has led to a new windfall in state and city funding to the New York City schools.

The group that filed the lawsuit, the Campaign for Fiscal Equity, joined the city teachers union in organizing the rally.

“Once again, after all our battles to get money put into the city of New York, the first thing they cut back are our children,” Ernest Logan, the president of another sponsoring group, the principals union, said.

He and other speakers stood on a dais just outside City Hall and spoke into microphones that boomed their voices for blocks around Lower Manhattan. A giant screen telecast their images, as well as video of the crowd.

Students and parents at the rally represented a wide swath of the city, from Brooklyn’s Park Slope neighborhood to Washington Heights in Manhattan to the Forest Hills area in the heart of Queens. Some carried homemade signs with slogans such as, “Cut Klein! Not Kids” and “The Bloomberg Curriculum: Dictatorship 101.”

Bloomberg administration officials said they held the briefing at City Hall just before the rally to emphasize how reluctant they are to making cuts. Officials noted that the education budget has increased by $4 billion, or more than 70%, since Mayor Bloomberg took control of the schools in 2002, and that city contributions have increased more steadily than those from the state.

Preserving the education budget from any cuts next year would mean forcing other agencies — such as police, fire, parks, and social services — to cut their budgets by 12%, the officials said. The current plan is for all agencies to face the same proportional level of cuts.

“The promise has been kept,” Deputy Mayor Dennis Walcott said. “While no one wants to cut the budget, let alone cut education spending, the economy is in trouble, we need to act responsibly, and we cannot address the gap without including an agency as large as DOE.”