Talk:Trade/@comment-5164622-20120604061741/@comment-5012038-20120604065231

You can buy cards by purchasing premium chest and brains from the in game. Go to Chest, tap "SHOP" to purchase brains and traps and CHEST for premium chests. You will need to buy Shop Items to purchase them.

Another option is to trade with other players. If you mean buying as in using real money to buy the items, that is against the ToS of the game.