Even if it is true that none of the extra fee weapons is overpowered by itself compared to the standard weapons, paying for additional weapons still provides an unfair advantage. If you buy the extra fee weapons and their characteristics differ in any way compared to the standard weapons, then you have the advantage of a wider array of choices of different weapons with different characterisitics, and therefore you can better select the optimum weapon in a wider variety of situations. Therefore EA is lying through its teeth when it says that the extra fee weapons don't give any advantage over the standard weapons.

Pay for more weapon options = paid advantage = paid cheating = no game purchase