I think it could hit 1 million. FFXIII-2 is currently somewhere between 1 and 2 million, I forget the final figures. Lightning isn't as popular as Toriyama says she is, so she won't be selling copies by herself. We can count on it selling worse than XIII-2 though, the interest has diminished a lot since XIII's first reveal.
How many copies? Would you say *whoosh* 10 million?
Eh... No, I don't think ten million... Look, I need your help. I live under constant attack. --- I'M IN DESPAIR!!! THE SIX YEARS FINAL FANTASY VERSUS XIII HAS BEEN IN DEVELOPMENT HAVE LEFT ME IN DESPAIR!!!
FFXIII-2 sold around 2.5 million the last time I checked. It might be at 3M by now I really don't know. However, I think LR will sell 1 million worldwide. Maybe 2 Million if FFXIII-2 is well liked and didn't piss many people off like the original FFXIII did.
I highly doubt LR will do better. The only people who will buy are FFXIII and Lightning fans. Maybe a few newbies as well. --- "When you come at the king you best not miss"