WUSTL is a great school, especially if you remain in St. Louis or the Midwest. I'm a native of the St. Louis Metropolitan area and there are a lot of affordable places to live. St. Louis is aptly referred to as the 20-minute city.
You can get to and from just about anywhere in the area in about 20 minutes. Overall, St. Louis is a large city, with a small town feel. My wife is originally from Georgia and in just under a year, learned her way around the city. St. Louis is a great sports town. You have the Rams (and the new dome), the Blues and the Cardinals. There are great malls like the Galleria (every once in a while you can run into a professional athlete there), the West County mall and others.
Apartments are affordable because there are a variety of options to choose from. Someone on the board mentioned the Central West End. This is a nice area that probably has some of the highest rents in the region. Go a little farther into the suburbs of South County, West County, or even across the river in Illinois (e.g., Edwardsville -- another nice and clean college town) and you can get a lot of bang for your buck.
I can share more about the city and the school if you have an specific questions.