If you activate the Perk Activation it replaces the pickup classes of the weapons so the have a different price, so if you play with the shop mutator you also have to write the Pickups from the Perk Activation to the Shop Mutator otherwise it would not work!
IJCWeaponPackPerkActivation12.MK23PickupP
IJCWeaponPackPerkActivation12.DualMK23PickupP
IJCWeaponPackPerkActivation12.M7A3CPickupP
IJCWeaponPackPerkActivation12.M7A3MPickupP
IJCWeaponPackPerkActivation12.FnFalAPickupP
IJCWeaponPackPerkActivation12.FnFalPickupP
IJCWeaponPackPerkActivation12.M99PickupP