What total and utter dog shit. Why does the market have nasty substances floating around it? Because the law has made it so. You could kill the vast majority of drug abuse overnight. Step 1, allow recreational drugs. Step 2, test recreational drugs for safety and chemical addictiveness, ban the most vile, and (this is the really important step) allow the one's that are pose minimal risks, and cover them with safety labels that describe the real risks (if any). Step 3, watch as the war on drugs essentially ends and human suffering rapidly declines.
Will some out there go do crystal meth over something that gets you high, cost loss, is safer, but doesn't fry you as badly? Probably, but they will be in the vast minority, in the same way most people don't go to bootleggers, but they still do technically exist. You would free police up to fight the truly nasty stuff and far more importantly, give illegal drugs competition.
Illegal drugs exist in a world without competition from anything other than alcohol. If you want to go have a nice trip, there is literally no alternative to illegal drugs. The result is that illegal drugs, which are horribly overpriced, win out. The real cost of of a trip is a buck or two. The street cost for a serving of some harmless shrooms is something more like $30.
Legalize recreational drugs so that people can test them and work on safe alternatives. Keep even mildly dangerous drugs legal so that people stop dying of impurities, which are, by far, the most common reason for drug deaths. Starve criminals of their funding. Watch as the world gets better.
That, or go fight another worthless war on synthetic drugs. I bet you will totally win it this time.