Well, I am ignoring the massive evasion a sales tax north of 10% would create.
And ignoring the massive evasion an income/payroll tax system north of 40% does create. Once again you fail to compare apples with apples and oranges with oranges
One of the benefits of income taxes is the cross-reporting which reduces evasion to a great degree. There is no cross-reporting in a sales tax. That's why they turn into VATs.