Second, what you call a "cult" is a position on taxes that has been studied by the Economics Dapartment at Harvard, not to mention many other economists. This is no pie in the sky proposition. Further, its already being done... Both Florida and Texas already use the Fair Tax model for their own state taxes. By your definition the legislatures of Texas and Florida are 'cultists'. Many of the studies you refer to, were bought and paid for by the FairTax organization - hardly objective.
Texas has a sales tax rate of 6.5%, and Florida, 6%. Texas has a host of other taxes you might want to check out:
http://www.window.state.tx.us/taxinfo/taxrates.html
But what do the relatively low state sales tax rates have to do with the FairTax?
And what do independent economic studies bought and paid for by AFFT have that prevents them from being even more valid that non-independent economic studies bought and paid for with endless amounts of our tax money with the obvious objective of perpetuating the status quo?
It's easy to see which group is more likely o be objectively honest ... and it ain't the government.