From CNN Money…
For $100 a year, “Office 365 Home Premium” customers can put Office on up to five computers (including Apple Macintoshes and Windows 8 tablets) and store up to 27 gigabytes of data on Microsoft’s SkyDrive cloud storage service. The subscription includes frequent software updates and allows users to automatically load their customized Microsoft Office settings on each different device.
You’ll also be able to use a temporary version of Office from any computer, even if the full software is not installed. Stop paying and you lose access, though.
Fortunately, you can still buy it the regular way and avoid subscription costs. But the price tag for the basic version is $140.