Cheap eats/hole in the wall in St. Louis?

Hi there - coming to St. Louis this weekend for the half marathon. We'll have a car, but are staying downtown, and I'm not sure that we want to spend a lot of time cruising around looking for/paying for parking, so recommendations within walking or MetroLink distance of the Savvis Center are ideal, although there doesn't seem to be a lot around. I am not looking for touristy places, even "famous" holes in the wall like Crown Candy or Ted Drewes or Pi but more for local favorites ethnic/cheap eats (i.e., taquerias, Asian of any sort, soul food, Cajun). I hear there are some good Bosnian and Greek places? For instance, Sweetie Pie's sounds like a must hit, as well as a number of places on South Grand (Mekong, Pho Grand, Bahn Mi So). Niche sounds very nice but is out of my price range. In those parameters, where would you eat? Thanks for the help!