Legalization of drugs, pros and cons!

[Cyclopea]

I'm "anti-drug". Don't like them, don't do them.
But I think all drugs including pharmaceuticals should be legalized and the taxes put towards treatment for addiction.
The practical problem with this is that there is a massive economy built around drugs which would collapse. If the black market was wiped out and most of the prisons closed by legalizing drugs what would replace this economy? What would happen to all the people who make a living on the black market? Would they sell Avon or what? It's not just "cartels" that make a living in the drug economy but lots of regular people too. There are not enough jobs in the legal economy as it is without displacing the massive underground economy and all the legal jobs that feed off it. Would the average street dealer be re-trained as an addictions counselor in the new "treatment economy"?