http://www.theverge.com/2012/8/21/3257406/windows-8-pro-price-upgrade-price
Microsoft's Windows 8 Pro software will be priced at $199 after a promotional price of $69.99 expires on January 31st 2013, according to one source familiar with Microsoft's plans. The software maker will also offer a Windows 8 to Windows 8 Pro upgrade option at retail stores for $69.99 until January 31st when the price reverts to $99.99.