If you are flying, you can take the Metrolink (light rail, 25-30 min) downtown from the airport and stay downtown. You can probably stay at the Drury Hotel, Holiday Inn, Marriott, or something comparable for under $100. You can then take the Metrolink to Wash U, which has a stop right by the med center (10 min from downtown). If you are looking for something nice and fancy, the Chase Park is right next door to the med center. <a href="http://www.chaseparkplaza.com/" target="_blank">http://www.chaseparkplaza.com/</a> A room can be had for $150-250 per night.