In GalCiv 1 you could sell things to other races for x credits now and y credits per week for z weeks. It was a great way to profit from trade goods, and to put financial pressure on other races. But that option seems to be gone in GC2, replaced by simple one-off payments. Is it something that must be unlocked via research, or has it been removed entirely? If it's really gone, is there any chance it will be making a comeback in a future update? I really miss it.