Learn some supply and demand econimcs before making such absurd allegations.
Legal heroin would still be run by criminals, terrorists and drug lords because it generates cash and the drugs are a relatively compact store of value, even at the lower legalization prices. I doubt the street price would decline much under legalization as that demand is inelastic. However the drug lords would lose margin under legalization which they would try to make up thru increased market share and volume.
Perhaps they'll all return to school and become mechanical engineers, computer programmers, and history teachers. I can just see it now...
ROFLOL!! By legalizing addictive drugs and ensuring unfettered public access TO those drugs, you will increase the number of addicts...which in turn INCREASES DEMAND...which allows the SUPPLIER to RAISE PRICES to WHATEVER THE MARKET WILL BEAR.
This is why there is PROFIT in selling legal things. Increased demand = higher prices. DECREASED demand, and/or INCREASED PRODUCTION (usually by a competitor, who gluts the market) DECREAS PRICES. If the product is in high demand and it's market value has lowered due to market glut, the price drop is TEMPORARY.
Once you control the market production of a super high-demand product, you can glut the market to discourage competitors....then simply create an artificial shortage in order to raise those prices back up and increase your own profit (uncontested by competitors) profit.
Don't give me the tired libertarian "alcohol and cigarrettes are legal" argument. Al Qaeda sells opuim, which is a heckuva lot more addictive and distructive than either of them.