We reported that $40 Windows 8 Pro upgrade offer will end on January 31, and new price for upgrade will be $200 for all from February 1. But the good news is, U.S. students will be able to upgrade to Windows 8 Pro for $70 from February 1.
When Microsoft announced the $40 upgrade offer to Windows 8 Pro, it did mention that the offer will last till the end of January, 2013. Later Microsoft officially reminded the users about the deadline and mentioned that the cost to upgrade to Windows 8 Pro will be $200 from February 1. But Microsoft has made special consideration for U.S. students and faculty members, who would like to upgrade to Window 8 Pro from current genuine copy of Windows XP (XP3), Windows Vista or Windows 7 OS after Jan 31.
Only and only the U.S students and faculty members will get a chance to download an upgrade to Windows 8 pro for $70 from February 1. Please note that in order to qualify for that offer, students will need to have a valid e-mail address through a qualifying education institution.
The offer will come to 22 more countries from February 21, additional 11 countries from March 7, and 16 more countries from March 19.
Source: Microsoft (Blog)