There are plenty of ways to save on computer programs. Here are a few options specifically for MS Office substitutions:
Desktop Applications:
iWork (Mac only)
Open Office (Windows, Mac, Linux)
StarOffice (Window, Linux, Sun Solaris)
Zimbra (Windows, Mac, Linux)
Online Applications:
Google Apps
Zoho
Microsoft Office can cost up to $399.99 US depending on the flavor. Most of the time you find yourself just needing to write a letter or create a budget in a spreadsheet. The tools mentioned above have become quite powerful and can accomplish most peoples needs for FREE!