Analysts Broadpoint Amtech, made an estimate that the $499 16GB iPad costs $270.50 US to manufacture. That means a profit of $228 for every iPad Apple sells. They also estimate that Apple makes up to $446 profit for the 64GB version.
A small list of various parts and prices: 9.7-inch LCD touchscreen: $100, 16GB Memory: $25, iPad battery: $30, Apple A4 chip: $15, Warranty service: $20. For the Full list take a look at MacObserver.
Apple asks $130 more for the iPad 3G enabled version, but Broadpoint Amtech Estimated that the 3G enabled iPad only costs $16 more to manufacture, that means way more profit for Apple.
There is just one thing we should not forget, it took a long time to create a product like the iPad, and that means a lot of man hours Apple needs to pay.