[Nicky91]

New cards and cosmetic items can be acquired at the Shop. The Shop accepts Gems, a currency earned from completing missions, winning duels in Solo Mode, or purchasing them with real money. You can only buy the Master Pack under pack(s) as well as the featured packs, but when you get a super/secret rare that belongs to a secret pack, you unlock that secret pack

see, you have that choice


either gems or real money, so it isn't a pay wall unlike other games out there