By comparing prices in the Netherlands, where grass was de facto legal, with prices in the U.S., Miron and Waldock figure the price of dope would fall by as much as half if the drug were legalized in the U.S. The RAND authors conclude it would decline even more, so legal weed (including tax) would cost only one-quarter to one-third as much as illicit marijuana.
FORBES: Dude, Would Legalizing And Taxing Weed Solve Our Budget Woes?