While downloading the Office suite app is free, you are limited to viewing previously made documents, and presenting them. To start a new document, or to perform any editing functions, iPad owners will need to subscribe to Office 365. A one-year subscription is $99.99 which can be paid as an in-app purchase. Students pay $79.99 for the university edition, and later this year Microsoft will make available a $69.99 personal subscription. Microsoft has not revealed the number of such subscriptions it has received from iPad users. Earlier this year, some analysts concluded that Microsoft was losing out on $2.5 billion a year in revenue by not offering the Office suite to users of Apple's iOS flavored slates.
source: SeattleTimes via Engadget