The components are a lot cheaper then you think for the manufacturor.
When I was working for a navigation company we were talking about adding gyroscope and accelerometer sensors in the device to continue tracking the path of the device when the gps reception is interrupted. The price of those sensors are only a couple of dollars (for mass production). The hi-res screen was by far the most expensive component at between 20 and 30 dollars depending on the model. (Ofcourse every penny saved at the bill of components translates into a much bigger cost reduction at the store price)
The ngp is a lot smaller then the ps3, and therefore a lot more economical to ship, and uses less material to build. There is no reason at all that the ngp should cost more to build then a ps3, there is no expensive blu-ray drive in there with lots of moving parts after all.
