Chicago already is one of the most expensive cities in the world -- No. 7, according to a report by financial firm UBS. But the cost of living soon could rise even more, if Chicago Mayor Rahm Emanuel gets his way. The Windy City mayor is pushing a $500 million property tax increase, the largest in the city's history, as a way to balance an almost $700 million deficit. On top of that, surrounding Cook County just raised the sales tax to the highest in the nation, at 10.25 percent, while considering a hodgepodge of other fees. And the state...