If it really costs around $900 to make, and they probably won't charge more than $500 for them, they're losing $400 on each one.
If manufacturing costs don't go down by the time they sell that many, assuming they can sell that many to begin with, then they lose:
$400 x 100 million = $40,000,000,000.
40 billion dollars lost. Sheesh. If they made all their own games, and reaped a full $50 from each one...:
$40,000,000,000 / $50 = 800,000,000.
That means eight games per PS3 sold, just to break even. But they don't make all their own games, so I don't think they can reap a full $50 from each game, and even if they somehow could, selling 800 million isn't easy. Games have enough trouble breaking a million...who can make 800 "million-sellers"? Or 1600 "half-million-sellers"?
Talk about ridiculous. I suppose if they did sell many, manufacturing costs would go down over time, but still.