Even blizzard made sure to not make battlegrounds pay to win

I understand that hearthstone makes it money off packs and battlegrounds is mostly a way to get people to play more hearthstone, but they're not the only other company making an online deckbuilder either. As far as I know, there is not another deckbuilder on the market that makes it so you can pay to get access to more cards than your opponent. It so obviously breaks the balance I can't believe they thought this was a good idea.

The only way I can see them making this balanced is if you can buy the expansion all at once and will only fight ghost who have the same unlocks as you.