+1 from me too, Open office is very good
if you must have Microsoft version due to using complex VBA etc then if you are a student ( or have someone in teh house who is in full time eductaion from reception class upwards) you can get hefty discounts on the full versions.
e.g.
Microsoft Office 2010 Student Pro Plus: SAVE with 90% Off | Software4Students.co.uk
reduced to < 40 quid from over 400......