http://www.insidermonkey.com/blog/apple-inc-aapl-pays-167-50-to-make-new-iphone-estimate-18498/
Of note:
"Moving up fro 512MB of RAM to 1GB raised that cost from $3 to $4, an increase of 33 percent. But the biggest jump in the cost comes from the chip that is used, made by QUALCOMM Inc. (NASDAQ:QCOM) the 4S chip cost $14 each, but this faster version costs $25 each, an increase of 78 percent."
Of note:
"Moving up fro 512MB of RAM to 1GB raised that cost from $3 to $4, an increase of 33 percent. But the biggest jump in the cost comes from the chip that is used, made by QUALCOMM Inc. (NASDAQ:QCOM) the 4S chip cost $14 each, but this faster version costs $25 each, an increase of 78 percent."