When I ran (and it was about 12-15 miles a week), I got about 6-8 months out of a pair of running shoes. I suppose if you are running/walking on really rough terrain (like torn concrete) it would only be a month. But, otherwise, that seems VERY odd.

I would spend about $75/pair back then. Now? I wear my shoes forever, and really, I hate new running shoes. No matter how well the experts tell me they fit, they make my feet fall asleep for months and months and months.