You're comparing the cost of Prohibition (which lasted for what, about 13 years?) to the cost of alcohol abuse for, I guess all of recorded history. You may be able to convice yourself that this is sound reasoning, but I doubt anyone else here will buy that crap.
I'm saying, in my opinion, the annual cost of Prohibition was less than the annual cost of alcohol abuse, alcoholism, rehab, detox, lost wages, hospitalization, etc. We can also compare annual deaths due to Prohibition vs. annual deaths due to alcohol, including DWI deaths.