SHANGHAI - Energized by the growth he's seen in China and excited about his ``very big vision'' for rebuilding California's freeways, ports, levees and hospitals, Gov. Arnold Schwarzenegger told reporters accompanying him on a trade mission today that he did not yet know what a statewide rebuilding push would cost -- but said it could exceed $50 billion. Asked about recent reports that he might back an infrastructure bond of $50 billion or more, Schwarzenegger said he's still negotiating with top lawmakers on the precise cost, but he is thinking big. --snip-- The governor's comments came after he visited Bao...