It would certainly be a tax on the poor, while it would be 'fairer' to tax all the ssame rate for income, it would not be fair to tax someone on expenditure without some sort of non-taxable commodities put on a no-tax list.
Poor people do not buy cars at any high rate, rich people do, and they may pay more per price in tax, they have the money to. Poor do not have the extra cash. HOWEVER, if they have less taken out of their check...and if they save it...
" ... to ensure that no American will pay tax on necessities, the FairTax plan provides a prepaid, monthly rebate for every registered household to cover the 23% consumption tax spent on necessities up to the federal poverty level. This is how the FairTax completely untaxes the poor, and lowers the tax burden on everyone else."