About taxing drugs;
cigarettes are taxed at a higher rate in Great Britain than anywhere in the world. We pay around 4.50 - 5.00 per pack of 20 here. ($1.60 = 1.00)
What has happened? A huge boot-legging / black market has evolved. You are constantly offered imported fags whereever you go. You can't walk into a bar now in some parts of England without being taken into the car park and get shown the contents of someones boot.
I walked into a shop the other day, in a completely different town to my own, and the guy in the front was buying cigarettes from "under the counter".
Profit in it can't be as "high" as in the drugs market, but lets just say, if people can profiteer from fags, they will do likewise if drugs were taxed.
The government here are still putting taxes up on cigs here as it is working; people are leaving smoking in droves. But those who are left are all smoking imports. They did one survey by collecting all the discarded packs from an entire football ground after a match and over 50% were illegal imports.