Doubt it, buying gold isnt even perm ban worst they will do is take the gold away if you havnt spent it that is
*edit because your not actually selling it your giving it away for gold which technically has no real money value you cant get introuble. I read somewhere on the offical fourms it is okay to give away beta keys so getting gold in return should be okay just tell them he was just returning the favor or something if they ask where the gold came from