No an upgrade (going up a major number, ie: 2 to 3) was always a purchase. Only the minor number updates (ie 2.1.1 to 2.1.4) were free.
You;ll need to go to the App Store and purchase Aperture. But before you do that make sure your system and OS are compatible with version 3.
If it is drag the current Aperture app from your /Applications folder to the trash and then go to the App store and buy it.
What happens to all my photo's. Do I save the current Aperture library somehow then upgrade?
The upgrade only will replace the Aperture Application, not the Aperture Library. But it would be a very good idea to make sure you have a working backup of your Aperture Library, before you upgrade to Aperture 3, for the first thing that Aperture 3 will do, when it relaunches will be to prompt you that your Apertrue Library needs to be upgraded to work with that new version - the backup will allow you to revert to your previous version, just in case something goes wrong with the library-rebuild during upgrade, so that you will be able to restore your library from the revious version and also still be able to open it with Aperture 2.
The steps you take to upgrade should be:
- Backup the Aperture Library
- Run a library repair and permissions repair (the Aperture Library First Aid Tools - in Aperture 2 this is called "Consistency Check", see Aperture 2: Troubleshooting Basics: http://support.apple.com/kb/HT2945) to make sure there are no problems with your Library while still running Aperture 2
- Move Aperture.app to the Trash
- Buy Aperture 3 from the App Store