Liverpool cashed in on Torres to the tune of £50 million and debate has raged on the size of the fee since his misfiring debut against his former club.
He has continued to fire blanks through February but his performance against Copenhagen in the Champions League on Tuesday was described as "fantastic" by Blues boss Carlo Ancelotti.
Wenger has often been prudent with his funds and he feels Chelsea paid too much, but would rather have seen them keep the chequebook closed.
"Torres was a last-minute transfer and, as a result, Chelsea had to pay for it," Wenger said. "We can estimate that Chelsea paid an additional amount for Torres, about 15%.
"Emotion and a lack of time saw the market value become inflated but, now, Chelsea could become even more dangerous. The trio of Didier Drogba, Nicolas Anelka and Fernando Torres represents a real danger."