You can get a very good pair of headphones for that price. As mentioned, Beats is overpriced as hell. You pay for the name. Boss is decent, but not the best.
Try looking into Sennheiser, Beyerdynamic, AKG or Audio Technica. It depends very much on what you want to use it for. Gaming requires different cans than heavy metal, which again requires different cans than classical or jazz music.
Also, since you want to spend that much money, I HIGHLY recommend going over to head-fi.org and asking there. It's a forum for audiophiles. Those guys know what they're doing, and they can give you a good recommendation. Unlike the BL forums.