Hi Sean,
You can always download the latest version of Army Builder you can use from our license management web site:
http://www.lonewolfdevel.com/
Log in with your license, then select the "View License Details" option. At the bottom of the page, you'll see links to the latest versions of Army Builder that are available for your license.
Paying our license fee allows you to access the integrated updates mechanism within the product, and entitles you to free updates when they become available. For example, when Army Builder 3.4 came out, everyone with an active license at that point was immediately given access to our new Mac version, plus the new PC version.
If you choose not to renew your license, that's fine too - you can continue using your current version of Army Builder, and download updates from our web site rather than using the updates mechanism
Hope this helps!