i spend 19$ a bag to fill 7 of my 8 pots so once in while i need to buy two bags.

 i'd say soil roughly cost me 23$ a grow when i m producing up to 200gr per grow, so not a huge cost in comparaison to what it would cost to buy 200gr of weed. and this is also true when i have added the nutrients cost and electric bill.

a grow cost me roughly 150$ all included for up to 200gr of weed, i'd say that's cheap.