If your goal is a QP/month, a 400 watt bulb can do that for ya, at much less cost than a 1k light. I generally get about a pound every two months with a 400 watt light accented with a few CFLs, growing in soil and ScroG'ing, and using a cabinet rather than a whole room. If you live in a state where punishments are related to number of plants, ScroG is safer than SoG, as the number of plants you have growing will be lower.