FFXII was made on a $20 million budget (No source, there is a link out there somewhere but I lost it :( ).
I'd say around $40 - $60 million is more reasonable, but in all honesty I don't think anyone here is qualified to guess. Alot of the costs for the PS2 FF's, like CGI, Voice Acting, story writing won't have gone up just because it's in HD (CGI now uses in game engine?). I've always understood JRPG's as a genre to be more cheap to develope, although maybe FFXIII's production values are wayyyyyy too high.
The developement schedule is seemigly alot longer and a bigger team but $100 million seems over the top, supposedly thats what GTAIV reached so who knows.
Also I think it should be noted that Square-Enix don't see FFXIII as one game, but as another franchise they can keep adding to even after FFXIV is out. We already know about Versus and Agito, but Square-Enix claim there'll be more. If FFXIII costs pioneer it to the popularity of say FFVII, even if it doesn't make much of a profit, there'll be alot of money to be harvested from Fabula Nova Chronicles.
So in conclusion, I haven't got a clue :P.







