TerrisH: At first I was like .. wait, are the Mooks human? Wut? Then I realized, duh, human wave tactics. Anyway, if you want to 'add more' humans, you have to build their towns. Same if your barbaric species have towns - however, I (being the ethnocentric that I am) want humans to spread easier, so there is an added charge to spread barbaric species farther than their initial area. If, however, the species as a whole migrates (could leave a tiny population here and there where they started from), well then that is cheaper! It is the full cost of creating a new one, yes.