You would gain a one month advantage on learning the motions of the game. Yeah it's only story mode, but you would still be ahead of the curve and have a better feel for the game than all who start on 11/10.
I would pay, maybe a couple pounds extra? Idk, i mean King Jamie brought up a good point. If the online was fully active and there was always people to play with i would pay 10£, no more.