HTC Nexus One
Nexus One's hardware cost $174.15
http://www.engadget.com/2010/01/09/nexus-one-hardwar ... »
The chips used for connecting the device to the networks have royalty costs associated with them as well.
The screen is most likely some proprietary stuff.. I can't talk for the Nexus One, but the Droid is made using Gorilla Glass...