Take the following with a grain of salt as it has not been confirmed officially by Microsoft. Tom Warren over at The Verge reports that sources close to Microsoft have revealed to him that Microsoft will make available the Pro version of Windows 8 for $69.99 until January 31, 2013.
That’s $30 more than the confirmed upgrade price that gets you a copy of Windows 8 Pro provided that you are the owner of a valid Windows XP, Vista or Windows 7 license. The retail price after the promotional period goes up to $199 from February 2013 on, which is the same suggested retail price of Windows 7 Home Premium, and $100 less than Windows 7 Professional.
This effectively is a price decrease of $100, and while retail pricing usually gets slashed pretty quickly, it indicates that Microsoft is using an aggressive strategy to push out Windows 8 to the Windows community.
Tom also mentioned that an upgrade from Windows 8 to Windows 8 Pro will be priced for $69.99 during the same promotional period as well. From February 2013 on, the upgrade will be available for a retail price of $69.99
The only pricing that has been officially confirmed by Microsoft is the $14.99 upgrade pricing for Windows 7 PCs that have been purchased from June 2 on until January 31 as long as they are eligible for the upgrade. This is only available for PCs that are eligible, so you best ask the store clerk or support if that is the case before you make the purchase.
You can register for that special upgrade on the official website. All other promotional pricing offers are available from October 26, 2012 onwards.
Pricing in other currencies should be roughly the same, even though it may be a bit higher in some locations like the UK or the Euro zone.