Amazon have got a promotion going where you can get a 3-user license of Office 2007 Home & Student for £54.99 (normally £89.99) when you spend £39.99 on one of the following categories:
* Desktop and laptop PCs
* Networking hardware
* Hard drives
This is the cheapest I can find for the package if you aren't a student (if you are then software4students.co.uk is cheaper @ £35 + delivery for the Enterprise edition).
Enter code OFFICED6 at checkout.