If you find yourself purchasing multiple similar types of products in the store, such as Wordpress or Joomla exploits, it might make more sense to purchase a pack of products instead. Packs give you access to many related products for cheaper than each individual product would cost combined. After purchasing a pack, you can also subscribe to future updates in the pack for a small, up-front fee. Once subscribed, you can receive all pack updates free of charge for a full year.
If you purchase a pack and don't subscribe, when new products are added to the pack, you must purchase the difference between the pack contents when you purchased the pack and the current pack contents in order to subscribe.