Running Shoes - Do they fit right and how to know?

Recent studies show that the cost of a running shoe does not assure satisfaction (http://www.nytimes.com/2010/10/23/health/23patient.html?_r=1&scp=1&sq=shoe%20fit&st=cse).  A recent article in the NY Times reports that athletes sometimes spend as little as $25 on shoes and are quite happy.  Although in my experience, a good middle of the line shoe (usually $80 - 120 retail), will give you great cushioning and support, you can often find that level of support in a less expensive shoe.  This may not work for everyone because not all feet are created equal, especially if they are flat.

The best and most advanced way to assure the best fit for a running shoe is to
1. follow my instructions on Howcast at http://www.howcast.com/videos/259469-How-To-Properly-Fit-a-Shoe.  Here are detailed instructions I published a while ago to make sure your shoes fit properly.
2.  Go to a running store with a treadmill - Stores like roadrunner sports or our local chain The Running Company can make the process more accurate.  You can see how you impact the ground using their treadmill and assure a better fit for your style of foot.  Different brands of shoes fit differently and sometimes the treadmill can save you money by helping you pick the right shoe for you.
3. If you have low arches or overpronated feet that flare out causing asymmetry in your gait, you can also use the treadmill to see the difference an insert makes.  Rather than buying a more expensive shoe that is stiffer and less comfortable, put in an insert and you will likely feel and run better.  Most stores will allow you to try them out.  I am personally unimpressed with some of the supposedly custom inserts some stores will upsell you.  Often, I find the less expensive off the shelf versions actually work better.  If you have a more severe foot problem, visit a professional such as a chiropractor or podiatrist and have custom inserts made. If done properly, they are more corrective and do last longer.