Sure, there are plenty of retailers which sell it - just do a search online. Also, if you have the appropriate MSDN subscription then you can download it.

For what it's worth, I wasn't a fan of Office 2007 (the version on your profile) but Office 2010 (for Excel at least) was a vast improvement. Plenty of companies still use Office XP or 2003, but Office 2010 is definitely worth considering before you fork out your money for a version of Office which is 8 years old?