Sales of Apple’s new iPhone 4S seem to be surprising even the most optimistic analysts, although the new phone isn’t really…new.

The 4S uses the same body and screen as the old iPhone 4, but it has a beefier processor, better camera and a few other, rather minor differences. According to iSuppli’s cost breakdown, the new phone’s bill-of-material (BOM) cost is $188, which is eerily similar to the old iPhone 4.

Basically the higher cost of the new camera ($17.6 versus $10.7) and processor was offset by the somewhat lower cost of memory and some other components and voila, the total cost remained the same.

Of course, Apple is continuing its somewhat strange pricing policy by offering 16GB, 32GB and 64GB models for $649, $749 and $849. However, the cost of NAND is in these versions is estimated at $19.2, $38.4 and $76.8. Basically the 64GB model costs Apple about $57 more to produce than the entry level 16GB model, but it sells it for $200 more. Sweet deal, for Apple, not the consumers.