You seem to be assuming that the price of everything will stay the same and then a 9% surcharge will be added?
That is not the case. The costs of goods and services will change because the corporate tax rate will change and so will consumer demand.
If you paid a 4% sales tax on a doughnut that you were charged a dollar for, but a 9% sales tax on a doughnut that you were charged 50 cents for, you'll end up paying less.
Herman Cains Phase one "enhanced plan" relies entirely on the "Super committee" And airy group of six that I defy anyone here to name, and a group that will no longer exist by the time of the election.