Quote Originally Posted by NPR
http://www.npr.org/blogs/money/2010/01/podcast_an_economist_gets_ston.html

"Fourteen states have adopted medical marijuana laws. We talk to Harvard economist, Jeffrey Miron, about what happens when drugs move from the black market to the open market. Do they get 100 times cheaper? Or instead, more expensive? Miron talks about the economics of prohibition, and reveals his drug of choice (which is legal) and one he would like to try (which is not)."
There was an NPR piece a day or two ago regarding legalization the its effect on prices. The upshot is that most people overestimate the reduction in price that legalization would create as well as the tax revenue legalization would generate.