The number of regions in the game wouldn't increase the price unless it needed multiple game cards somehow(... That could happen actually, except it won't because it'd need to be DSi exclusive in that case.), or such, since the only thing that multiple regions would need is space for data on the game card

Though, PokeWalker and the IR tech may run the price up, but I hope not, or at least not too much... D=
True... I just hope it's not too much if it does up the price, otherwise, many people may not be able to afford this =/