I guess I just don't see the problem with rich people having more left over after paying the sales tax than poor people do. The problem is that they can spend

I guess I just don't see the problem with rich people having more left over after paying the sales tax than poor people do. The problem is that they can spend it on capital which then lets them earn more and more wealth. Maybe you also disagree with the claim that inequality is itself a problem? That would put you in the minority in most places. If not, then consider this: sales taxes, due to their regressive nature, increase inequality and funnel more wealth to the top. Taxes on unearned economic rents (such as land value taxes) are progressive, decreasing inequality and spreading wealth more evenly throughout society.