It all depends on how much $$ the OP is willing to spend and how much the guaranteed BC seat is worth to him. You can pay more now and be guaranteed a BC seat, or take your chances on one being available at OLCI. If you buy the seat now, will you regret the extra expense when you find out at OLCI that the BC cabin is only half full? Will you regret it more than you will regret NOT spending the money and finding out at OLCI that the flight is booked solid in BC and in the back?