$100 for APU
$100 for 8GB GDDR5 RAM
$50 for 1TB HDD (they'll need large HDD due to forced game installs)
$25 BR Drive
$25 rest of mobo and innards
$25 for 3D PSEye
$15 for DualShock4
$15 for various connectors and packaging
$5 for powercord/brick
That's about $360 in total parts for the package. Not including any assembly, storage, shipping, or retail margin.
AT A BEST CASE SCENARIO you'll see it at $399 for some base sku with no game and Sony selling it at a reasonable loss. More than likely we'll see it at $429 to $499. Same as neXtBox.
$15 for DualShock seems low.
Shipping is a huge cost. Who do you think has to pay for transporting millions of PS4's to stores.
Manufacturing, R&D are also huge costs.
$400 is a low estimate for the cheap SKU. $500 for the bigger HDD.