Well, let's see - there is no income tax so the durg dealer's customer isn't paying tax on his income (nor does the dealer owe tax on his income). Will the dealer charge his customer the sales tax an forward it to the government? Not likely. so how does this fair share of taxes get paid?
Every time something legitimate is purchased.
This isn't rocket science.
(Wanna bet he charges the 23% and keeps it, making him richer than before? "Hey, kid, sorry about the price goin' up, you know? This Fair Tax thing is a bitch, huh?")