[Lobo_do_Norte]

53,160 / 3 = 17,720 : average number of copies for each support (PS3, Xbox360 & PC)

Then, dispatched around the world to the different resellers, I'm sure that doesn't make that much... Maybe 1,000 or 1,500 copies per store and per region ?
That said, I'm pretty sure that it's really out of stock everywhere, 'cause a thousand of pre-orders is easily reached on sites like Amazon or Game or whatever.