There are millions of people in that situation. We don't really know. Imagine the life insurance industry: it is all predicated (as far as sales to big ticket clients) on the fact that the cash value build up is tax deferrred. And when you start taking money out it is a LOAN so the IRS doesn't tax it. So individuals must no longer pay those huge life insurance premiums to protect their estates.
The missing chunk of money you are trying to find has been identified-- it is the payroll and income taxes. You should not expect to find 18% in addition to income and payroll taxes because they are probably about 15% of overall costs right there so all you need are 8% more and you are at the needed 23% savings that the FairTaxers have been estimating are embedded in the cost of goods.
The reason it is unlikely is that all of the money that the FairTax models plan to collect have been identified. The largest chunk by far is the income and payroll taxes. Now that we actually know that these were intended to be retained by the business in order to reduce prices, we know where the FairTax model expected the money to come from.
I am not one to believe that compliance costs will go down much for most companies since almost all the accounting needs to be done to run the business, and for public corps in order to meet SEC regulations.
There is hardly any corporate tax to be wrung out.
Jsut to clarify mys response, when I said "This will not ever pass because every dollar already accumulated would have its purchasing power destroyed by about 17%", I am referring to a version of the Fairtax where it is somehow mandated that wage earners get to keep their entire pay check. THis would be inflationary and that is what I am saying sill not ever pass.