My friend setup one of his bedroom for a small grow, problem was he had a 4x8 table setup and had a single 1000w light, with no more cash...lol... well i told him that he should bring back the bulb exchange it for 2x430 bulbs, i helped him out with the extra cost of getting the second bulb, extra socket, and wiring... i wired up the 1000w ballast in series (for some reason it didn't work in parallel) and he's been runnnig this lighting setup for a couple of grows now.... so for the cost of 1 ballast, and getting 2 lights...i would have to say that this helped out on the initial cost of starting up...as he has now earned enuff cash to buy a second 1000w ballast...