With Medical Cannabis at $60 an 1/8th in Chicago - you could see a different kind of "Black Market".
Everyone thinks of the "Black Market" as someone growing weed in their basement or something.
But the truth is: At $60 an 1/8th (that is $480 an ounce) - people are just going to drive to Colorado (or some other legal state) and load up on $100 ounces and drive back to Chicago and sell it for $300. That is $180 savings over the dispensary and the "Black Market" dealer is making $200.
Right now, as we speak, people are loading up in legal Recreational States and driving to illegal States to sell it at a profit.
When Canada's Cannabis Market becomes as saturated with product as Oregon - then you will be seeing people drive to Canada and load-up with cheap product (just like they did during prohibition).
During Prohibition, bootleggers would drive across from Detroit into Canada to pick-up Canadian Whiskey and they would bring it back to the USA and sell it a huge profits.
No different today.