I've done the math on my own. Including watts, nutes, seeds and everything consumable, I can grow dank ass weed for a couple of dimes a gram. Yup. Doesn't count my time tho. Or the medium and other equipment. I've had my lights for a while now and they have easily paid for themselves over and over again. But, that's based on hempy bucket and Lucas formula. I reuse my perlite over and over again until it winds up mixed in soil for a house house plant. Then I buy more. And it only takes minutes a week to tend except for harvest and trimming of course. Even that I do chilling, having a beer with the tv on. I'm a simple/lazy grower tho and don't obsess over it. I think I could get it down even less if I went organic. That's for personal tho. I don't sell product.
Now imagine if it was legal. I mean, all us Po folks on a budget trying to survive won't be paying $20 a gram period. Now, if I could get dank for a dollar a gram I would only bother growing, cause I do enjoy watching the plant grow.