the cost of illegal drugs is and always has been, for the most part, the costs involved with doing business outside the law. marijuana and hemp rope are both derived from the cannibis sativa plant. production costs should be similar, and thus, price per pound should not vary greatly. opium and poppy seeds come from the same plant. likewise their costs of production should be similar.
the vast per pound difference between hemp rope and illegal marijuana (and poppyseed/opium) is what supports a huge criminal class. a matching amount is extracted from the taxpayer to support a huge class of law enforcement drones, judges, lawyers, prison guards, etc.
can we as a society afford these two huge parasitic classes? if we legalize everything, the cost is some dead junkies. but wait, they’re already dying like flies anyway.