Looking for a cost effective way to move up to Windows 8? Arguably the best deal at the moment is available from Microsoft directly. If you're running a licensed copy of Windows XP SP3, Windows Vista, or Windows 7, you can get a Windows 8 Pro upgrade for $39.99.
Keep in mind this is a download -- if you want a DVD copy shipped to you, it'll cost $69.99. We'd say stick with the download though, because in addition to saving you money, you can create a DVD or USB key copy very easily once you are up and running.
As a nice add-on, WIndows 8 Pro users can, for a limited time, get Windows Media Center as a free add-on here.
Thanks to forum mmeber ryder_ca for sharing all of the deal details!