Nothing but a free market.
Do you presume if drugs were legalized, only people who could afford them would take them, or are you presuming those who can't afford them will receive government subsidy to finance their habits?
People would have to set their own priorities.
Are you suggesting that we do away with the WOD and make it 'open season' on drug addicts, so that we can shoot to kill before they kill us?
You should always be able to defend yourself.
Just doing away with the WOD isn't going to solve the problems of drug addiction. In fact, I believe it will cause the problem to increase. What is legal is generally considered moral.
The problem of drug addiction is not societies, it is the expected result of recreational drug use, and is a problem for those who choose to have it. If someone wants to rid them selves of the problem, they have to want to.
Morality is the province of the individual, his home and his religion, while the laws may reflect commonly accepted morals, we should not look to the law for the definitions of what is moral or even wise.
Sure, a 'free market' for extremely addictive products. Get 'em hooked, raise the prices - then the government steps in and adds taxes. You still end up with people who steal/kill in order to finance their habits. As prices go up, the 'black market' would also grow, thus bringing the concerns you have about rat poison, et al, back into focus.
"People would have to set their own priorities."
They do that now. Don't need to legalize drugs for that to happen.
"we should not look to the law for the definitions of what is moral or even wise."
All laws are about legislating someone's morals. Anything that is legalized automatically becomes more accepted by society (abortion is a good example of that). I don't happen to believe this society needs anything else to bring it closer to falling apart, and legalizing drugs would do just that, in my view.