$287 vs $100/$110 is the difference spent on the Xbox 360 cpu/gpu vs the new 8th gen consoles cpu/gpu(apu).
Consoles have far less expensive hardware than last generation, and even more so when you factor in inflation:
BOM = bill of materials
In 2005 Microsoft spend an estimated
$247 (
$287 with inflation in 2013 dollars) on the CPU/GPU of the Xbox 360 Launch BOM.
Sony spent an estimated
$100 on the APU in 2013. Microsoft spend an estimate
$110 on their apu. Of course you can factor in MS/Sony got a better deal by going with a single chip solution from one single chip maker.
How do we get these numbers:
Xbox 360 BOM =
$525 (
$606 in 2013 dollars via factoring in inflation)
sources:
http://www.theregister.co.uk/2005/11/24/xbox360_component_breakdown/
http://electronics360.globalspec.com/article/2210/xbox-360-teardown
http://www.alphr.com/news/hardware/80708/isuppli-reckoning-the-xbox-bill-of-materials
PS4 BOM + manufacturing cost is at
$381.
Xbox One
minus Kinect2 BOM = $396 ($396 in 2013 dollars). Alot less spent on the console internals this time around.
A less important stat, but just for the fun is comparing Xbox 360 adjusted to inflation to Xbox One/PS4 there is a
$210 and
$225 drop respectively in hardware component cost this generation. Of course getting to the heart of the matter is they spent less on the cpu/gpu.