Seriously... you’ve never set down with excel and built a couple of models.Seriously, taxing my savings an additional 30% when I spend it sounds like a poor model to me. If you have no savings and lots of debt, I can understand your infatuation with the FairTax.
The 30% would be no more than you pay before you retire. Your taxes would not go up. They would be whatever you were accustomed to before you retired. Less if you spend less. More if you spend more. But if you're a person who saves a lot, has a company that contributes a lot, has made a lot off your investments and doesn't want your kids to pay inheritance taxes, or you want to gift them and your grandkids.... it makes a LOT of sense.
If you plan on retiring with 200k and social security to live off of, it doesn't make much sense. But then you got big problems either way if that is your retirement plan.