Reducing corporate taxes could allow prices to come down to compensate for the 9% sales tax. This is the claim of the Fair Tax people anyway. More likely, since you have a choice in whether to buy something or not, unlike your income taxes, if the price is too high the seller will have to bring it down and can as long as he is making a profit, remember less taxes to the fed.
RE: Reducing corporate taxes could allow prices to come down to compensate for the 9% sales tax.
IF WE ALLOW COMPETITION TO FLOURISH, YES.
If Companies need not worry about spending so much time on accounting and other unproductive tasks, with a FLAT 9% tax ( THE LOWEST IN THE DEVELOPED WORLD ), Companies will compete with each other to lower the prices of their goods to gain YOUR favor.