Great, Rob, let's see your detailed revenue neutral derivation. After all we showed you several for the FairTax.
The revenue neutral calculation you are talking about is a calculation of how much stuff is sold that will be subject to the Fair Tax, divided by the amount of revenue that needs to be replaced.
It does not show how much those sales volumes will change to changes in price. Nor does it show how people taking action to avoid paying 30% tax will affect the calculations.
I could just as well say America uses 146 billion gallons of gasoline per year, so we will charge $16 per gallon tax on every gallon sold. and raise $2 Trillion. That is a revenue neutral calculation too. It doesn't mean anything in the real world though for obvious reasons.