Some residents bought their homes for as little as $35,000.
The contract isn't official — and residents don't get any money — until 2009. If the sale goes through, nearly every owner will get more than $1 million.
About 80 percent of the town's shareholders who cast ballots approved the sale, while 17 percent opposed it, according to a statement Wednesday from the town's corporate office. More than 97 percent of shareholders voted.
Briny Breezes may be the last large waterfront property in all of South Florida, CBS News correspondent Mark Strassmann reported. It is 43 acres nestled between the Atlantic ocean and Florida's intercoastal.
But some residents are unwilling to put a price on paradise.
Resident Tom Burns says Burns says his lifestyle isn't for sale. He doesn't want to give up his ability to have his boat docked outside his home.
"I don't want to give it to them," he told Strassmann.
The overwhelming support will help heal some rifts created by the proposed sale of the 488 mobile homes, said Gay Sideris, who has lived at the park with her husband since 2001.
"I don't think there is anyone that lives here that doesn't love Briny," said Sideris, who stands to get about $1.5 million for a $155,000 investment. "We're happy it went through because it will be good for us and our family, but we're sad we have to leave. Now we can just concentrate on the great two years we have left here."
The 43-acre property is a down-market relic of old Florida surrounded by multimillion-dollar homes and splashy high-rise condos.
State and local officials still must approve new zoning to accommodate the 900 condo units, a luxury hotel and marina proposed by the developer, Ocean Land Investments of Boca Raton.
Palm Beach County officials have raised concerns about adding a high-density development to South Florida's cluttered coastline. The community is in a hurricane evacuation zone and has few ways in or out.
The town began as a strawberry farm in the 1920s. A group of regular visitors bought the property in 1958, and it became a town in 1963. It is run as a corporation by a board of directors, and the residents own shares based on the size and location of their lot.