Turbulence about running shoes

I've been paying attention to running shoes lately because I know I need to replace my current pair. Despite my attempt to preserve my Nikes by substituting the insoles I've learned (thanks to some helpful advice via the Runner's World Loop) how to assess a shoe's true condition. I've moved past the denial stage and have gone back to my original insoles. Although the Turbulence 13's felt great with the replacement insoles (after I cut them to fit) the difference in heel height made me worry about the possible effect on my knees since I'm a mid/front foot striker. I'm hoping that I can get one more great run out of these shoes at Saturday's race.

With the original insoles intact I did what should be my last run before the 5K. I started at a moderate speed because I still have some upper leg tightness and wanted to warm up before stepping up my pace. I increased the treadmill speed every minute until I reached my target. Overall I covered 2 miles at 8:41, a pace I attained by running the last few minutes at about an 8:00/mile.

I've decided to go somewhat high end for my next pair of running shoes. Adventure Girl and others have advised me to look for shoes at running stores because those places carry better performing shoes than retailers like Foot Locker. My wife found some very good shoes at a Foot Locker as did I with my original Nike purchase. AG also told me that sometimes higher priced shoes cost more because of non-functional design elements. I don't care what my shoes look like but if I can get 5 seconds per mile faster on them I'm happy to pay.