Link to full articleOffice 2010 Home and Student, which includes Word, Excel, PowerPoint and OneNote, US$149 and lets a family install the suite on as many of three household PC
Office 2010 Home and Business, which adds the Outlook email client $249 and can be installed on up to two of the buyer's PCs
Office 2010 Professional $499 and can be installed on a pair of PC
In addition there are "key card" options for all the above discounting them 20%-30% that allow you to upgrade the "starter" version shipped on many PCs.
Professional Academic, an edition available to K-12 and college students, staff and faculty. The edition contains the same application mix as Office 2010 Professional, can be installed on up to two PCs and will cost $99.