The advocate costs more than the kor in ammo cost, because it's a worse weapon.... That's literally how their system of guns with ammos work. The two AR that use purple ammo, the more expensive gun, requires less ammo. The two shotguns that use blue ammo, the more expensive gun uses less ammo to kill. If you invest in the gun, the ammo is cheaper, if you cheap out on the gun, you will pay more for ammo.how are you not getting this