Many software vendors offer software to Architecture students for free or at reduced prices.
Adobe Creative Suite - The Design Premium version of CS 5 is available from the Computer Store (University Center, Lower Level) for $599. (Retail $1899)
AutoDesk - Join AutoDesk's Education Community for access to free software. The Autodesk Student Version software incorporates all the functionality of professional licenses, but includes a print banner making the software inappropriate for professional, commercial, or for-profit purposes. Note: 3ds Max is a 30 day free trial only.
Google Sketchup Pro - Download the student version of Sketchup Pro for $49. (Retail $495)
Rhino - Student price is $195. (Retail $995)