Zarate .... Or perhaps Pato who both were teenagers and their clubs (lazio and Milan) spent a lot on just to turn out to be worthless money.
Unless a young player is extremely good (young Aguero, neymar, C.ronaldo) clubs should never spent a fortune on those young players.
And I'm sorry, watched 5-6 games for Verona last season and Iturbe reminded me a lot of Zarate. Great dribbler with great shots but awful (even shiit ) when it come to his decision.