Transfer money from crypto account to normal bank account I'm totally unknown about this topic so I come to all of you with my question.

I sold something online and the buyer wants to pay me through his cryptoaccount. But then he told me that there is an issue with his account and that he needs me to buy a Steam gift card of 50 euro. When I buy this I will receive an e-code that he needs to convert crypto into money? 

Is this all legit or is this a total scam?
You cannot transfer money from crypto to banks directly. You would have to sell the crypto currencies on a special marketplace for cryptos, after that you can get them paid out to your bank account. But you will have varying exchange rates depending on which amount you will sell and what the actual market price is at the time you sell it. Plus additional transaction costs.