I just don't see how making it legal will drive the price down. Heroin is $8.00 a bag by me. There is no way that making it legal, making it FDA inspected and compliant, taxing it, and selling it in stores and storefronts will make the cost go down. I just don't see that working.
I also don't see the Gov making it legal and not doing all of the above. Just let the drugs come in, and be sold, and be legal with no Gov regulation or taxation. Not happening, IMHO.