I'd say it depends on what your goal is. If you only want to grow 2 plants at a time for personal use and don't want to get too serious about growing, then there's nothing wrong with a 250w. It's a pretty popular size for people just starting out, although many times people "outgrow" them rather quickly and end up buying a bigger one after the first grow. So, really it's up to you. If you have your heart set on growing your own ganja, then maybe you would be better off starting with something larger. 250w isn't really all that much power. Your average microwave uses around 1500w. Then again, you don't run a microwave 12 hours a day. Depending on where you live, a 250w hps will cost around $10 a month in electricity.