Theres about 20 MS stores in the whole USA.
An NO, the Windows tablet x86 will NOT sell for $200~300. That is the WART version. The X86 version will sell for $700~1200 (depending on config).
If MS sells the WART 10" for $200, it would be at a $45 loss, but that is fine as they NEED to grow their market share ASAP to get people to try it out and developers to make apps for it. If the user buys 10 APPs a year + x number of songs, it will pay for itself quickly.
At $300, MS would make a $50 profit, which would be preferred - but could cost them sales. They need a fire sale since they are dead last in the market.
The only tablets that most people seem to be intrested in, is the x86 version which has all the problems of current x86 tablets. Heavy, thicker, far less battery life (4~5 hours), noisier, hotter... and of course, cost too damn much. THAT will not sell enough to be a knock out... and the WART version at $300 or $400 is way too weak against the iPad and Android devices already on the market.
At a $200 loss, they can sell them a lot easier over an Android.