Of course, you can buy as many application's packs as you want to create promotions and contests with Cool Tabs. All our packs have discount and have no expiration. 
You can have a look at each app's price and features here. 

And if you want to buy a pack, access your Promotion Sell Page. Click the app you are interested in. On the following webpage, choose how many apps of the same type you want to buy.