The iLife package (GarageBand, iDVD, etc.) used to be on the gray DVDs that came with Macs. When Lion was introduced, Apple stopped distributing disks with their computers, as they did with yours. When you do a full erase and reinstall, which I presume you have now completed, these apps are not installed by default. Per a post by user ds store:
If your machine originally came with 10.7 or 10.8, then follow this:
Restoring iLife applications after Internet Restore of OS X Lion or OS X Mountain Lion
If you erase install OS X Lion or OS X Mountain Lion on a new Mac that shipped with OS X Lion or OS X Mountain Lion installed, you can download iPhoto, iMovie, and GarageBand from the Mac App Store.
- After installation, start (up) from OS X.
- Double-click the App Store icon in the dock.
- Enter your Apple ID and password.
- Click Purchases.
- If you haven't previously accepted your bundled iLife applications within the Mac App Store, you should see your iLife applications appear in the Accept portion of the screen. Click Accept.
- You may be asked for your Apple ID and password once again. Your iLife applications now move to the Purchased section. These applications are part of the software that came with your Lion based computer. Your account will not be charged for them. Click Install to complete installation of your applications.
Following these steps, you should be able to install the version of iLife that was tied to that model Mac for free.
This isn't the same as iWork (Pages, Numbers, Keynote). I'm not sure if those were ever free. The App Store has the titles available for $20 each. Pages has not garnered much praise, though. Many users feel it has been dumbed down. Many useful features have been removed. The number of 1 star ratings is pretty high for the current version 5. Most users would tell others to stay with version 4.
You can get iWork '09 on disk from Amazon for $20. That is Keynote version 5, Pages version 4, and Numbers version 2.