Well seeing as you can break down cards and "build" new cards in this game you are going to be able to get the cards you want eventually. Besides without the ability to trade cards with other players you won't actually see cards that cost "more" then others, this is where you get those ridicules prizes in other card games where it's P2W and you can't play competitive tournaments without buying those 10 rare cards that cost 25$ each, every time there is a new best deck of the week.
Don't forget when playing other people in this game you get paired against others with an equal amount of win/lose ratio to balance things out, if you don't have the cards to play at max potential because of lack of cards you still get paired against people you can beat, which totally eliminate the P2W aspect.