OAKLAND -- A federal study now under way finds the cost of building the new Bay Bridge -- specifically the signature 525-foot suspension tower -- could explode again, this time by almost half a billion dollars. Almost ten years ago, Caltrans estimated it would cost $1.3 billion dollars to replace the eastern span of the Bay Bridge. Five years ago, the state said it would in fact cost almost twice that much -- $2.5 billion -- for a new bridge. Last year, Caltrans had still another projected cost: almost $5.3 billion dollars. Wednesday night, Caltrans spokesman Jeff Weiss acknowledged the...