Mine wear down quickly because I walk a lot on concrete. I don't really know how long they last from a quality perspective because I don't generally keep them long enough to find out, but since I don't wear very high quality shoes, it probably wouldn't take long.
However, this year I bought my first real investment shoes (2 pairs of Stuart Weitzman boots--yes I love reminding all of you of that), and I expect they will be my friends for at least a decade, barring any sudden changes in my feet. They are both fairly simple, equestrian styles that won't date (I know some people question the longevity of OTK boots, but I don't see mine dating just because they happen to be a little taller than a standard riding boot).
I do not typically get things re-heeled or re-soled, but until recently I haven't really liked my shoes enough for it to be worth it...sad but true. However, my Star Ling boots which I wore all last winter, are really worn out, so I may get them cleaned and resoled at some point. They are the comfiest boots I own. Like slippers. The only problem with getting shoes fixed up is the time I have to go without them. I'm VERY dependent on my footwear.