As for the craigslist stuff?
Right now just about anyone can study up right and grow cannabis that will sell for at least minimum price. What's going to be interesting is when the concept of 'quality' cannabis becomes mainstream.
When you have to grow quality to make money in cannabis... that's when you're going to see some larger operations selling off used equipment as they go out of business.
I would say that is already the case on the west coast. Its taken me a year and 3 harvests now just to get to a decent product and even then most of it is still fluffy crap. I see in Colorado there are already tons of recreational shops opening up. Me thinks they are going to be selling a lot of fluffy crap for awhile. If its this hard to get good stuff, there cant be a lot of people doing it right and getting good stuff.