Naturally occuring drugs have existed since the formation of the planet - unless you plan to co-ordinate a wholesale, worldwide weed-killing program, they always will. As most of them grow naturally then money/cost isn't an issue, until it becomes a profit making trade like opium poppies.
Manufactured drugs(i.e LSD/amphetamines/MDMA) were/are created by scientists/pharmocologists as part of research into a certain condition or to cure/control illnesses and diseases - in many cases it is later discovered they have uses for completely unrelated conditions or they become recreational.
The price or availablity of a drug is also not an issue because those who want it will have no compunction in using whatever criminal activities they can to afford it, no matter how desperate or depraved these tactics become. Those who supply will always find an alternative substance to feed the addicts in times of scarcity.
MDMA was first introduced on the streets in the early 80's, contrary to the myth that it was the ecstasy boom of the Madchester scene etc, and was used exclusively by the rich, back-bench politicians and club owners. In fact, the Ministry of Sound was started and is owned by a bunch of backbench MP's.
And do you not agree that the Vodka in your name, along with all alcohol, is as destructive as any drug? It's just that because alcohol is legalised it is acceptable in society.
I'm sorry but I don't think any of us have a right to be holier than thou or think we are better than others because we aren't addicted to heroin and the like, but I appreciate the fact that you at least entered into a discussion and didn't enter into the 'got a problem, let's nuke it' mentality of some I could mention...