iSuppli have stripped an iPhone 4 to its constituent parts, and found that there are $188 worth of bits and pieces within a 16GB iPhone 4. To be a touch more precise, it’s $187.51, including $28.50 for the retina display (the most expensive component), $10.75 for the A4 chip, $2.60 for the gyroscope, $0.65 for the accelerometer.
At launch, the iPhone 3GS was pegged at $179, which has since dropped to $134 as part prices have declined.
So, an iPhone 4 costs at least $188, just for the parts. Add in labour, development, advertising, shipping, software development and everything else, and you and $199 for the 16GB model doesn’t sound so bad — until you realize that AT&T is making up the difference in exchange for your immortal soul.

I love these cost analysis posts! Excellent work! And very interesting!
I agree with krakajap. It’s really nice to know the phone makers aren’t making money hand over fist on the service fees AND the cost of the device
Not to mention the fact that Apple has invested a lot into architecture and design of their A4 cpu as well as the whole design.