Microsoft prices Office 2013 at $99.99 — a year. That’s quite reasonable for me.
Microsoft debuts Office 2013, a modern reimagining of Word, Excel, & more with subscription
People can choose to pay $99.99 a year for a single subscription that covers up to five users or devices, an extra 20 GB of SkyDrive cloud storage (on top of the free 7 GB of space), 60 minutes of Skype calls per month, and premium licenses that ensure households get as-they-happen software updates.
Folks can instead opt for the nonfrills, single person Office Home and Student 2013 package that costs $139.99. But this has a bunch of catches. With the one-time price option, you won’t get software updates, the additional SkyDrive space, those handy Skype calling minutes, or Outlook, Access, and Publisher. If you want Outlook, you’ll need the pricier Office Home and Business 2013 version, which costs $219.99. Source: VentureBeat
With Adobe also doing the subscription model, I am convinced this is going to be the common model in future.