Then in my opinion, it's not much more expensive to include 4 more characters (and the dialog would seem pretty... hollow). If however, the dialogs, and the direction of the dialogs, are all unique (in that, say, Haruka and Chihaya both respond with different ideas, and dialogs are tailor-made to suit them), then I can kinda see exactly how much content you need.
That better be the case. You can't replace producing stagnant Iori with unique Haruka + Chihaya dialogue though :/ there's a reason someone is called a "fan".
Also, there's still that fact: The VAs were already paid. Unless Rie Kugimiya got less yen than Imai Asami, NBGI had just wasted some money
That would be void if Rie Kugimiya actually do get less than Imai Asami from the beginning though
Come to think of it...
Namco and Microsoft believe, based on their previous success with the iDOLM@STER, they will achieve the same result because they believe the fan base is more willing to accept exclusive titles. Which means Microsoft is willing to cash out the money to keep it that way if it means lots of Microsoft point sales.
I still think that selling the dang title worldwide via total free-regionization would cash in more money than what Microsoft would pay.
Think: Microsoft won't pay so much as to suffer monetary loss only to keep Microsoft points selling. NBGI is getting less than if they sell the DLC directly. They can create iM@S points dammit, or simple PayPal stuff, whatever works.
Via total free-regionization, people outside Japan can buy the game (and subsequently, DLCs) too, cashing even more money for NBGI
But I do have to admit, this kind of game is not exactly popcorn, selling it outside Japan might not yield that much money
Also:
Producing Hannah Montana? Dear God no, please