With the clubs two best strikers - Robin van Persie and Nicklas Bendtner - both out injured for expected long periods, Wenger knows he will need to bring in a top class goalscorer if the Gunners have any hope of clinching the title this season.
Wenger said: "It depends on Bendtner. How bad it is. If he is out for two months, there is no way - we will need someone absolutely.
"There is still a 50-50 chance that we sign somebody. But it's my responsibility to spend the money in the right way, why should I splash it out and pay £10million or a player who is worth five?"
It is believed Wenger is targeting Toulouse striker Jean-Pierre Gignac who will cost the club about £12million whilst there is still some interest in West Ham's Carlton Cole and Wolfsburg's Edin Dzeko.