You may also want to try a higher-end shoe store. I go to a specialty running store where they measure all parts of my foot, analyze my gait, and don't grumble when I try on 15 different shoes. They charge about 25% more than the same shoe at other stores, but they make sure it fits correctly. Some manufacturers make half sizes, wider or narrower versions, and other such modifications that aren't available at generic stores.

Also remember Ray Jardine's advice (no, not corn pasta): feel free to modify your shoes as you see fit. Cut and mangle them until they're comfortable. Punch new lace holes, shorten the tongue, draw a map on them.. whatever you like <img src="/forums/images/graemlins/smile.gif" alt="" />

This advice does apply more to trail shoes rather than boots, but the same sort of logic applies. I bought boots at MEC where the sales rep insisted I needed 8 pounds of leather for $400. When I went to a specialty outfitter, I got ultralight, ultracomfortable goretex boots for $150. (I now normally wear runners, but still like my boots for very mucky areas)