Very few people can move up early and under rolled and make it stick. You will spend far too much time worrying about the money and your BR to play your best. Take a shot if you want, but I still believe that 25BI's minimum is the trick. You can actually afford to lose 10BI's while learning the next level, meaning you won't lose 2 quick ones to variance and have to move down so quickly. It will also allow you to just think about the session and bet amounts and not look at the cashier every time you reload.