After the state’s first attempt to tax online purchases was foiled by an Illinois Supreme Court ruling, online retailers will start collecting a 6.25 percent tax on customers in the Land of Lincoln starting Sunday. The high court determined in 2013 the state’s first “Amazon tax” law — aimed at leveling the playing field between online and traditional brick-and-mortar shops and also at drumming up revenue for the cash-strapped state — conflicted with federal tax law by singling out …