With all the discussion around pricing the past few weeks, it's very interesting that Apple is using a IAP model in one of it's apps
Aside from the new icons, the updated page also reveals in a footnote
that GarageBand will become a free basic download for all iOS 7 devices, joining the other five iLife and iWork apps that became free alongside the release of iOS 7.
GarageBand will, however, include in-app purchase content from Apple, with
additional instruments and sounds available for a fee. Licensing fees associated with some of those sounds had been the presumed reason why GarageBand was left out the original move to make Apple's iLife and iWork apps for iOS free of charge, and it appears that the company has settled on in-app purchases as a way around this issue, offering basic functionality for free and then premium content through the paid upgrade options.