It's the tax man

This story comes up about once a year or so but it's still amusing. South Carolina profited from the prohibition in an unexpected way when they enacted a law a decade ago requiring marijuana dealers to buy tax stamps. They didn't expect to sell any. It was a ploy to prosecute for tax evasion when they busted dealers but it turns out the stamps, at $3.50 each, became collector's items and they do a rather brisk business in them. Oddly, the more expensive stamps for other illegal substances don't sell at all.

Of course if they legalized the plant, they would no doubt make a whole lot more money.