In that case bring a player that doesn't have question marks over his head, spend the required amount of money to bring that top, ready made player. As someone that likes Ashley Young, I wouldn't mind Perisic if he was reasonably priced and wasn't expected to be one of the consistent difference makers, what really bothers me here is that we are adding a player that is not really better than our current options, he is far less effective than some of them.
If I'm being perfectly honest, despite my posts in this thread I know that Perisic is an adequate player, I'm just disappointed by the fact that he doesn't really have any upside compared to a young player because despite his age he has the exact same question marks than the one you would have on a prospect. My philosophy when it comes to transfers is that you spend big on a 28 years old player only if he is a confirmed top player, otherwise you either go for bargains or young players with upsides.