if large international companies were to involve themselves in the business of growing and distribution of marijuana, prices would most surely decline. There would be a chance of adulteration via delivery method ( chemicals in papers like in cigarettes etc.) however regulations as simple as disclosure rules would suffice. Still, most of the public would either grow their own or chose to purchase "safe" pesticide free weed from small local growers and chose their own delivery method (bong, papers, vaporizers) just as they do now.
Ok so basically right now prices are at P1 given the red demand curve and the green supply curve. When supply increases to the purple curve, the quantity available will increase from Q1 to Q2 and prices will decrease from P1 to P2. Think about it this way, if there was just a McDonalds, they could pretty much charge whatever they want (a monopoly). But when you have McDonalds, Wendy's, Burger Kind, White Castle, etc. there is more competition, so prices go down. Tell me if this doesn't make sense.
supply side economics is pretty easy to understand unless we are talking about commodity trading and speculating, somehow I doubt there would ever be a futures market for weed, but you can speculate on tobacco futures so who knows. but whether prices rise or fall is a non issue. The only consideration is whether or not the government is ever going to allow it's citizens to live as fully informed adults making decisions about their health and lifestyle without interference from a nanny state.
i totally agree with you;i think they'd have to meet/beat home grown quality if not it will go back to bis as usual... interesting point tho Opener!!