Fort Lauderdale commissioners vote tonight on a preliminary proposal to build a new City Hall set to cost taxpayers millions. Mayor Dean Trantalis says the plan calls for a 14-story building that could house nearly 600 employees. Construction is estimated at about $268-million, financing over 30 years would bring the total cost to nearly $725 million. Opponents want the city to buy an old building instead and or let taxpayers have the final say.