Hi, it s in order to awnser to your reply Dan !
Actually, I apologize for this comment, I thought the unobtainium's buildings were like 6 and the others were 3 or stuff like that... I ve probably exchanged the values in my mind, and I ve already changed it !
I m a new player, and had a bit of difficulties to understand some parts of the game, but now I got it (I think), and I m gonna try to spread it