How much did Mesut go for? 55? I don't think so.
They're both Turkish, so obviously you don't know them better than us. And you're twisting words because nobody said Arda is far better than Mesut.
He went for 12+1 millions because he has 2 years remaining in his contract. If we didn't sell him this year, we would not be able to sell him for higher price next year. You can't sell anybody from Turkey more than 15 millions even if he's Ronaldo or Messi. Because Turkish league doesn't have the market for it. If Pastore played in Turkey, do you think he would have gone to PSG for over 40 mil? Of course not. Would you buy Melo from us for 24? Of course not.
It's not how much you can sell a player, its how great performance you get from him. We will see how he plays at Atletico. He's going to double his value in 2 years.
Just like Hernandez. Ferguson got him for 7 millions and he plays in every game. Do you think his value is same this year? Can Juventus buy him from Man Utd for 7 millions? If he was Italian or Spanish, Man Utd would never got him for 7 millions. They got him for so cheap because he's mexican.