Expensive is fine since it is reusable.
At some point it itself becomes a target. It has to be able to get almost 100% kills, otherwise the enemy can swarm it with cheap drones, destroy the expensive installation, then continue as before.
At some point it itself becomes a target. It has to be able to get almost 100% kills, otherwise the enemy can swarm it with cheap drones, destroy the expensive installation, then continue as before.