As a peaceful mod alternative with military stuff still being demanded.

Thr simple idea is to limit it to military stuff. Bullets, guns, armor, turrets, walls, vehicles, fuel, equipment, repair kits, fish

A more complex varient is as follows
Instead of specific items, you have to provide arbritrary combat power. Roughly as a combat sim, armor/turrets/walls determines defense, ammo/guns/research determine offense, repair kits, robots, fish, fuel, determine support.

Each zone would cost some amount of offensive and defensive value, with support adding a multiplier. Multiple types of things adds to the multipliet as well.

So you have to provide all types of military equipment, but never actually have to fight.