I agree wholeheartedly. One problem, however, would be that I suspect the illegal suppliers would merely undercut the 'official' sources' prices, would be prepared to supply in much larger quantities than the 'official' sources, and would be happy to supply during what could be termed 'unsocial hours' - I doubt many chemists would be prepared to stay open all night for the purpose of giving succour to addicts.

Otherwise a good, if somewhat Bohemian, idea. I'd go for it.