i have very flat arches. go to a good running store (not sportmart). have them measure your feet and fit you with the right shoe. they may also recommend arch supports that you can slide in your shoe for additional support.
Just fucking go to RoadrunnerSports.com and use their "ShoeDog". It asks you a series of questions like your height and weight and arch type and then it shows you all of the shoes in that category.
That link is fucking ugly and I don't know if it will work since they track the session ID in the url which is annoying.
If that link doesn't work, then go to:
1) http://www.roadrunnersports.com
2) on the left you will see a thing that says "Shopping Tools" - mouse over that
3) in the menu that comes up is "Shoe Dog" - click on that
If the sole has worn out on your shoe after "a few hundred miles" - it isn't a sign that they wear too quickly, it is a sign that you need new shoes.
They are going to fail after about 400-500 miles anyway - the midsole foam that is, so if the exterior sole is gone, the midsole is long since toast.