I'm guessing "down market" folks would be the ones that might grow their own. Making them the "artisnal growers".  Growers can produce about 1 gram of pot per watt of light, growing four plants using a 600-watt HPS lamp could produce about 150 grams or 5.0 oz per plant. . Do that 4 times a year on a 90 day grow cycle, you have 80 ounces. I smoke weed every night before bed(sleep like a baby) and likely would never use more than 3 ounces per year. I'm guessing numbers like that reduce the need for the black market.