From Nov.2011- Nov.2012:
Beginning of last year: 1 pair of vapor 9's lasted about a month and a half.
Spring time: 1 pair of barricade 7's lasted about 3 months, the replacement lasted another 3 months
Summer to fall time: 1 pair of CB 4.3's lasted me about 4 months together with replacement.
Just bought a pair of CB 3.3's during the black friday sale and expect that to last me another 4 months with the replacement.
Spend about $400 per year on shoes, really need to cut down on those shoes....