[iso1631]

10% sales tax in many states, upto 13.5% in some areas.

Vast majority of income is not spent on luxury goods attracting those high rates -- rent/mortgage payments, electricity/fuel, transport, etc

[pvaldes]

Don't focus in the percentage, is not the important concept here.

Is a luxury to replace the oil in your car? We pay a 21% more.

You can see it from a point of view of privilege and pay less, let say 4%, so you don't care to think about it, but this does not change the problem. The problem is that you are paying 4% more, without receiving anything for it.