This is great info from iSuppli Corp about iPhone, they said that the 4GB Apple iPhone costs only $245.83 to manufacture, with the 8GB model checking in at $280.83.
see what they said below
That touchscreen that everyone is popping tents over only costs $33.50, with the touchscreen controller adding a mere $1.15 to the price. In fact, Apple stands to make a healthy 50% profit on both versions of the iPhone sold, with the costs of the 4- and 8-gig models only running $245.83 and $280.83, respectively