Moore's Law Is Dead thinks that Valve basically got a bargain bin deal from AMD, who had a bunch of chips they thought were going to be used in a MSFT tablet, but that tablet got cancelled.
So, Valve did some scrapyard engineering, and got a discount on these things that were otherwise never going to be used for anything.
He estimates a total cost to produce of $425, estimates MSRP between $450 to $600, depending on just how hard Valve wants to fuck MSFT with their own leftovers.
https://youtube.com/watch?v=sJI3qTb2ze8
If this ends up being remotely accurate, it would be basically a corporate demolition of Shakespearian quality.
Gabe... Gabe was once a MSFT employee, you see.
A disgruntled former MSFT employee, you might say.