I dont have any rent/mortgage I own my home. Outdoor can be grown for dollars. Just some organic teas nothing else. 10 200g smart pots. Cost would run arround 100-300 per lb witch I can resale for 1k-2k per lb. I know your talking about indoor. I can still grow very cheap my PGE is on the care program.
Congrats on not having rent/mortgage but this isnt the norm at all.
Combine most peoples mortgage with electric costs (even if you are on care) nutes, equip and supplies, and that profit margin just became a hell of a lot smaller if we are talking about a retail price of 1-2k