I had done some quick calculations and couldn't get the embedded tax above about 9% (employer SS+Medicare + tax on profits) + costs of collection and no one could convince me that the cost of collection was up around 15%. That would have implied that the total cost of collection in the entire economy was around $1.5 trillion/year. It might be a lot, but not that much.
Even with this I still like the FairTax. I could accept an 18% net increase in prices to keep my gross paycheck and eliminate all income and payroll taxes.
That won't work because it would screw people with accumulated wealth or on a fixed income. It also wouldn't help us be more competitive with foreigners.
The only workable approach is lower gross salaries, equal to what we take home now, with prices that remain the same for domestic goods.
Income tax is in the embedded tax, too. Did your numbers include inocome tax?
You are only looking at 1 step in the production cycle. The retailer obtains their inventory from a distributor, the distributor from a manufacturer, the manufacturer from his suppliers, raw materials or sub modules. Add them all up.