My mom doesn't have Excel but she needs it to do her new job... she doesn't really want to have to purchase Microsoft Office as a whole (unless of course that would be cheaper).
Does it have to be Excel? I'd recommend visiting openoffice.org and downloading free version of Excel called Math. Works just as good and you can save in Excel format.
Also, since you're aware this isn't a video game deal you're looking for, you should have posted it in the Other Deals & Requests forum.