you should not have been avoiding the tax before. you are supposed to report those purchases on your state taxes and pay the sales tax (if your state has a sales tax).
but only stupid people would do such a thing...
Especially since this "stupid" person pays more than one third of their income in taxes already, and some states like NY are considering holding tax refunds because they have no money.
No worries, my new W-4 going in will mean no more interest free loan for any state.