Shortly after iFixit tore down the iPhone 4S, iSuppli also took its turn with the iPhone 4S and evaluated the cost of the materials that go into the handset. According to its analysis, the iPhone 4S 16 GB costs US$188 in materials and and extra $8 to build, a dollar value that's close to the $187 of the iPhone 4. The 32 GB has a bill of materials of $207 and the 64 GB is at $245.
Inside the iPhone 4S, the most expensive part is the NAND flash memory which costs $19.20 in the 16 GB model, $38.40 in the 32 GB and $76.80 in the 64 GB model. iSuppli also notes that the NAND flash is from Hynix and not from Samsung or Toshiba which were seen in all previous iPhone and iPad models. The second and third most expensive components are the mechanical/electro-mechanical parts which costs $33, followed by the wireless radio which is a custom part from Avago and costs $23.54. For all the nitty gritty details head over to iSuppli's report.