Arsenal boss Arsene Wenger is reluctant to buy big during this month's transfer market.
He said: "The danger, if you buy because you are desperate, is that you overpay and you have no time, no insurance - unless the player has already played in the league - to know whether he will immediately strengthen the squad.
"If, however, you buy because it's someone you are after and there is specific weakness inside the club in his position, and it's an opportunity to take the player, then it is a good moment.
"I do it only when I feel it is the right moment."