Hearthpwn

EDIT: Change of question

How do I use those cards you find in stores that can be used for Hearthstone? (The once that are worth around 20 euro)

Naxxramas without a doubt.

FOR THE LOVE OF GOD MAN GET NAXX!

Get Naxxramas. Second wing has Loatheb, the most used legendary of Naxxramas, and actually full Naxx is the way to go. You can try playing Arena when you would get bored on hoarding gold for Naxx, consider these as "one pack for 150 gold" so don't spend all you've acquired from other sources. Playing Arena would also help you understand card mechanics better, and thus prepare you for constructed play or even infinite arena play (you can win more than you've invested on arena, but it's very hard).

naxx... just naxx

Naxx until the 4t quarter, fifth is not that necessary, then first quarter of blackrock mountain and congratulations!! you have patron warrior, no really the deck mostly uses basic set and adventure set cards

EDIT: Changed topic.

Now I'm thinking about just buying the rest of Naxx...

I want to use one of the cards that are worth 20 euros that can be bought in stores, but how do they work?

And are there other options to add balance to my account?

Nevermind, figured it out.

Someone please close this thread, cuz I don't need it anymore.