If your employer participates in the Home Use Program (HUP) and you qualify to take advantage of this program with your employer you can download the Microsoft Office Enterprise suite for $9.95. DVD backup media available for $12 more, though if you can burn it yourself to a DVD or even CD medium you may as well save yourself the money.
First, obtain your HUP Program Code from your employer.
Then, visit:
Microsoft Home Use Program
Using your work email and program code you can enter your order. $9.95 is a download only, a bit more than 500MB. The product key will be emailed to you and displayed on your order confirmation page.
The 2007 versions of the below programs are included in this suite:
Word
Excel
PowerPoint
Outlook
OneNote
Groove
Publisher
Access
InfoPath
Microsoft Office Enterprise $9.95 with employer home use program 
