You aren't "untaxing" anything.
It would be a hell of a lot simpler to define those things not to be taxed and then just not tax them. No administering bureaucrats for the 'prebate'. I have said before, those things should include food, primary housing, healthcare, and the energy to heat/cool that primary housing. Just. Don't. Tax. it. It doesn't get any simpler than that.
If the concern is that someone might live in 7500 square feet instead of 750, so what? They still have to furnish that, (more taxes furnishing 10X the space), they still will have 'stuff', they will likely have more elaborate equipment to tend to the grounds. All that will generate revenue.
As far as prebates not being a redistribution scheme, yes, they are. It takes money collected from people who spend more on the necessities (as set up) and gives it to those who spend less. Who gets to decide how much is 'just right', versus "more than your family needs". Now I ask that for a reason, because I live somewhere where there are a whopping 8 hours of daylight in the dead of winter, and temperatures reach -30 pretty commonly. Someone who lives in a more tropical latitude will decide whether or not I need heat? Whether or not I use too much and should be taxed on the "excess"? How will you, or anyone, as a practical matter decide? Or will we all be stuck with a one-size fits none average, gimmicked like the inflation figures?
Nope. No thanks.
10% for Jesus, the government should be satisfied with an equal share, and the rest I bust my ass for for me and mine. Stuff the Federal Government back in its (Constitutional) cage and it won't need more than that.
I like everything about the Fairtax except for the “prebates”.
If you start listing exemptions, you just open up a whole can of worms.
The prebates = the IRS does not die.