So you basically want 10-12 pounds every 60 days. That's around 5000 grams, so you're going to need five 1000 watt lights, with air-cooled hoods or cooltubes, a fan strong enough to cool all of them, more fans for room ventilation, probably some air conditioning, enough electrical circuits with enough amperage to handle that kind of load, nutrients, a tester for ph and ppm, good genetics. Oh, and enough growing experience to hit the 1 gram/watt 'holy grail'. If you don't have that, then add more 1000 watt lights, probably 3 or 4 more.

You'll also need a veg room, and probably a germination area, and lighting and cooling for that.

You won't even come close for $500-$600. Multiply that amount by 10 and you'd maybe have enough, assuming someone is handy with tools and stuff and can do all the labor. There's no really cheap way to start pulling 5-6 pounds a month. If there were, everyone would do it, and then it wouldn't be worth doing.