While we tried to give guided missiles a niche, they are just not a great unit for humans to use because humans need to get a lot of continuous value for their units. However, there is one niche that we have not explored, a niche that would signify the "cheap" cost in the guided missiles description. What if we removed the maintenance cost from the guided missile? So now, while the missile still remains a weak weapon, it has a niche for a player whose primary concern is money. If you are already breaking the bank on your army, this is a way to supplement more forces....consuming your Air Slots for more power at no ongoing cost. Flavorwise, though of course missiles get maintenance (everything does), in the grand scheme, missiles that just sit in their silos need less maintenance than modern troops and aircraft that are training and moving about.