Microsoft have confirmed its pricing scheme for Windows 8.1 ahead of its October 18th launch day. If you already have Windows 8 then you can just update it to 8.1 for free but if the user is directly upgrading to Windows 8.1 then they have to pay the given rates.
Costumers from US can purchase Windows 8.1 for $120 and Windows 8.1 Pro for $200. An upgrade to Windows 8.1 Pro from a device pre-installed with Windows 8.1 will be of $100.
In New Zealand, the official download will be starting at 12:00am on October 18th.