This also reminds me of Robin's IQ-gated, test-requiring would-have-been-banned store, which would discourage people from certain drugs without making it impossible for the true believers to get their hands on them. I suggest such a store be located way on the outskirts of town accessible only by a potholed road with a single traffic light that changes once per presidential administration, have a surly clerk who speaks heavily accented English, and be open between the hours of two and four on weekdays.

Something sort-of like that already exists.