When I calculate the cost to grow an ounce it is not simple because of the equipment costs. If I spread out the cost of the tent, lights, pumps and fans, pH pen, pots and such, over 3 years, and then add in the ongoing costs of electricity, nutes, seeds, additives and all the things necessary to keep the plants going, the total is around $50 per ounce of dried buds. Power is the single largest expense and even a couple lights shows up on the monthly bill. A commercial op can gain an economy of scale that a home grower cannot hope to match, but quality and specialities are where the home grower can beat the commercial guys, growing strains that are impractical for shops, like long flowering sativas, and letting them finish. There is regular "good quality" and then there is exceptional. There is a movement toward growing exceptional organic flowers, I have met some fans of this trend and sampled some amazing flowers that will never see a dispensary shelf. It would be impractical for a shop to grow this quality because it would not be profitable due to the price pressure.