If developer Bruce Ratner has his way and a basketball arena is erected in Brooklyn for the Nets, Menachem Friedfertig’s building would be in the midst of the grandstand seats. The property, at 622 Pacific St., is at the heart of the proposed $2.5 billion Atlantic Yards project, and its placement makes it a critical piece of the development puzzle.

The Crown Heights developer is driving to the net for a deal, hoping to force Mr. Ratner into a big payoff.

“I have the winning lottery ticket and I want my $4 million,” Mr. Friedfertig told The New York Sun.

Mr. Friedfertig bought his building at an auction for $382,000 in early 2003, before the Ratner plan was made public. Mr. Friedfertig pushed ahead with a plan to develop the building, with medical offices on the first floor and five stories of residential condominiums above. He even went so far as to hire architects and get permission from the city’s Department of Buildings.

One factor that could dull Mr. Friedfertig’s edge over Mr. Ratner is eminent domain. The state, which owns most of the property on which the Atlantic Yards development is to be built, has the right to claim private property for public use in exchange for fair market value. The state traditionally coughs up the bare minimum.

“Eminent domain should not be used as a cudgel to make property owners lower their bids, that is immoral,” Mr. Friedfertig said.

A spokeswoman for the Empire State Development Corporation, Deborah Wetzel, said it is too early in the process to comment on issues of eminent domain. Mr. Ratner has refused to comment publicly on his negotiations with local landowners.

Despite the risk of eminent domain, Mr. Friedfertig’s threat to wring millions out of Mr. Ratner is formidable because he has the city’s approval to build his development.

“In the case of eminent domain, Ratner has to prove his case for why he needs the property, and the owner also has the right to prove the property’s worth,” said a local developer, Henry Weinstein. “Once the city approves building plans, it adds a lot of value to the property and it is that much easier to prove its worth.”

Mr. Friedfertig has met with Mr. Ratner’s lawyers, whom he said were “very nice and cordial, but they didn’t offer enough money.” He would not disclose how much they offered.

“I am waiting for Ratner to make a realistic offer, or I could just go ahead with the development,” Mr. Friedfertig said.

If Mr. Friedfertig builds his development, it will raise the price tag, making it tougher for Mr. Ratner to buy him out. It will also make claims of eminent domain more challenging because it will mean displacing residents and businesses.

“I have calls from people also inquiring about flipping the property,” he said, explaining that someone could buy the property from him for around $4 million and then flip it to Mr. Ratner for a profit.

Architects Joe and Moshe Friedman have drawn up plans for Mr. Friedfertig’s building, and the developer expects that each condominium could be sold for about $1 million – the same price Mr. Ratner has paid for other apartments that have stood in the way of the Atlantic Yards development. An additional $1 million to $2 million could be generated by the medical offices, bringing the total for the developed building to $6 million to $7 mil lion, Mr. Friedfertig said.

“I have all the plans and the proper permits, so I could build the building and then it would be worth even more, making it even tougher on Ratner,” he said. “If Ratner makes millions – and I hope he does – then let him share it with the little guy.”