It's been pointed out to you hundreds of times that your bogus guess of "50% rate" for the FairTax is based on nothing at all but wishful thinking and your own smokescreen. And that is clearly shown by the carefully arrived at derivation of 23% in the paper where all reasoning and mathematical work are shown.
In contrast the "work" you depend upon to spew out such senseless blather is that of William Gale and the President's tax Panel which not only had no reasoning or mathematical derivation, but merely blurted out numbers based upon questionable presumptions and showed nothing of their work to allow checking by real economists.
There is no "40-50% sales tax" except in your dreams. You should pursue your career as a salesman as you'll obviously never make it as an economist.
The FairTax exists only in your dreams.