There's much more than the main SoC in the price of the console. MS doesn't pay the same price for components because they have to source almost all of them, and they have additional licenses to pay. Not sure how much this adds up, but it's definitely not a wash for a similar product.Basically if there is nothing else other than what is known from the current leaks from VGLeaks, then Orbis is going to cost significantly more.
Sony makes their own components, including the camera sensors. They make their own bluray drive, their own lasers, passive components, batteries, many chips and communication parts. They even have their own fabs for the main chips of the PS3. They are among the creators of bluray, they have less royalties to pay to anyone.
Microsoft must pay for Kinect. They need third parties for many components, including the powerful IR light source, two sensors including one custom, batteries, they have to license the PrimeSense technology, because MS didn't invent the Kinect. They must pay for a third party bluray drive. It looks like the billions that have been invested by the proponents of HDDVD was wasted (if the goal was to cause both to fail) and MS will now have to give money to Sony for every console sold if they want a bluray drive.
(just trying to get into the mood of the title here)