Hi, Stacy--
I couldn't agree more with Karen. For your first pair, you really should go to a specialty running store. They look at your feet, watch you walk, ask specific questions about your running habits and then make shoe recommendations from there. If price is an issue, let them know; they can certainly recommend less expensive shoes that will still be the right type for you. Running shoes are so advanced now; so many are designed for people that over-pronate, but if your foot is neutral, or if you under-pronate, wearing shoes that are designed for over-pronation could actually cause injury after a while.
Once you know which shoe is right for you, then you can go out and try to find some bargains. Lots of brands have outlet stores, and
www.roadrunnersports.com has tons of shoes. Sometimes you can get lucky and find the shoes you like at huge discounts because they're being phased out for newer models.
One word of caution--if a new version of a shoe you like comes out, don't assume you'll like it as much as the old one. They usually change at least a few things, and sometimes those changes really affect the way the shoe fits/feels. Unless it's a model you've worn before and know you like, don't buy it until you've tried it on.
Good luck and enjoy--running is great!
-Marie