Ok, so me and my bud have finally decided to get a 250 watt HPS. Thanks for yalls help on that one. Ive been searching and i can't find any 250 watt HPS's that are switchable to MH. Is that not available on only a 250 watter? What exactly is needed to switch between the bulbs? Is it just the bulb or is there something in the ballast as well? And finally, Ive read a lot of posts advising against used or refurbished light ballasts. However we are on a budget so lower prices are very appealing. Are the refurbished lights really that bad?