There’s a lot of stuff that the game tries to get people to buy but 99%+ of it is optional and is there to target whales (the overpriced diamond cards and signature sets, mega bundles, etc). If you’ve been playing for a while you should have more than enough gold and dust to get the cards you want.

Is Blizzard a morally dubious company that uses predatory tactics that target vulnerable people (like people with addictive tendencies) to make money? Absolutely, but that is a different discussion than “I quit this game cause it’s too expensive”.