Ammo Cost is a weapon statistic in The Last Stand: Dead Zone.
The ammo cost of a weapon determines how much is needed to use the weapon on a mission or raid. The ammo cost is essentially a one-time fee that must be paid before the weapon can be used on a mission; once the mission begins, survivors have unlimited ammo, but must still reload via clips. The ammo cost of each weapon is added up and calculated before each mission, and the compound must have enough in order to use the weapons on the mission; players cannot initiate the mission if the total ammo cost exceeds the amount of available in the compound.
The ammo cost of a weapon is influenced by the weapon's Capacity and Attacks per Second statistics. Extended Mags will increase a weapon's ammo cost. The 80's Action Movies and Hardcore books increases the total ammo cost used on a mission, while the Ammo Conservationist book reduces it.