Picture this: It’s April 2016. Your income tax return is due. While you still have to pay the federal income tax, there is no longer a state income tax.Sounds good, right?Would you trade not having to pay Georgia’s income tax, which has a top rate of 6 percent, for a sales tax as high as 14.5 percent — more than double the current 7 percent sales tax rate in Bulloch County?It could happen.But, despite the idea’s growing popularity, the Georgia Budget and Policy Institute, a nonpartisan think tank based in Atlanta, urged caution in a report it issued last week.