with the right genetics and a little scrog training you can yield 6 oz with a 250W being used through veg and flower.... my friend grows Romulan clones in a scrog setup in a 2' x 3' area and pulls right at 6 oz dried and cured every 13-14 weeks.... it takes him 3-4 to fill the canopy and 9-10 to flower....
not sure how much you're looking to get or how much you consume, but that amount seems to last between harvests for him.... he also uses a conversion bulb during vegging.... hope that helps a bit....
remember guys.... some people just don't have the capability of running the bigger wattage bulbs like some of enjoy.... gotta still try to help out the small setup personal growers....