I have never seen it for less than $350, so this is a great deal for those who need a copy. This is the full retail, not an academic or OEM version. For those running cracked or not-business-legal (academic, OEM purchased without the accompanying hardware) version who would like to be legal but had a hard time personally justifying it because of the price, this is as good as it's going to get:
http://www.newegg.com/Product/Produc...82E16832106076
Be aware, however... X5 will be out in a couple of months, so they're probably clearing their shelves.