Accommodations for the Grad Expo will be available on campus in the Union Club Hotel (which fills quickly) with room prices ranging from $109-$129/night. Mention the "Big Ten+ Grad Expo" when you are making reservations.
Blocks of rooms are also available at the Hilton Garden Inn in West Lafayette (just a few blocks off campus) for $99/night; and at the Holiday Inn City Centre in downtown Lafayette for $105.99/night. Use "Big Ten+ Grad Expo" when you are making reservations at either of these hotels.
Additional off campus hotels can be found in the Lafayette-West Lafayette area. Travel times to campus vary.
Purdue University does not recommend or otherwise endorse any specific off-campus hotel.