Beancounters over at iSuppli have fiddled with their calculators and concluded that the entry level, 16GB iPhone 3GS has a BOM cost of $172.46 and a manufacturing expense of $6.50, for a total of $178.96.

Last year iSupplie estimated that the old 8GB 3G model cost $174, but there's a catch. Although the iPhone 3GS 16GB retail price is $199, just like the old entry level model, thanks a different service provider plan, the total cost ends up considerably higher.

Bear in mind that the BOM cost doesn't include other costs, including R&D, shipping and distribution, packaging, royalties and various accessories in the package.

You can find a detailed breakdown at iSuppli, here.