Arsenal have made one significant signing, adding Switzerland midfielder Granit Xhaka from Borussia Moenchengladbach for 30 million pounds ($39.49 million).
Their defence was found wanting in Sunday's 4-3 Premier League defeat by Liverpool as a backline including youngsters Rob Holding and Calum Chambers was exposed, prompting grumbles of discontent among Arsenal fans with the club again looking ill prepared for a title challenge.
"We're not scared to spend money, but to buy in itself is not a quality, to buy good players is," Wenger told journalists on Thursday. "This club has been built on that.
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"The transfer policy we have had here has helped build the club. I know we haven't done as much as many people but we are out there," he added. "I have made 400 transfers in my life and I know every one has a rhythm that you are not the only one to decide on."
Arsenal are interested by Valencia defender Shkodran Mustafi, according to reports in the British media, but Wenger refused to reveal any specific transfer targets.
"I would like to reassure you that we are not afraid to spend the money we have and we are working very hard," he continued.
"You can pay huge amounts of money for average players, there are plenty of those, but to find the ones who will strengthen your squad is more difficult.
"Buying calms the fans of course but we have to make sure we spend it the right way."
Arsenal continue their Premier League campaign away at champions Leicester City on Saturday.
($1 = 0.7596 pounds)
(Reporting by Ed Dove; editing by Clare Lovell)
