Get an extra month subscription to Microsoft Office Home for free each year when you renew your subscription.

This probably works for other editions but I have only used Office 365 Home.

Before you add the new subscription at www.office.com/setup go into your Office 365 account and turn off Automatic Renewal.

Then when you renew your subscription you will get an extra month for enabling Automatic Renewal. See the screenshot below. This is the second or third time that I've done this saving an additional 11% each year.

Of course, you don't pay the full NZD165 price because you should always buy your Office subscription on sale - you can buy the subscriptions in advance and add them to your account and they will be queued to automatically renew.

This year, I bought Office 365 Home for $80 at the PBTech 2016 Boxing Day Sale. It is only NZD102.35 right now which is the cheapest NZ deal at the moment according to Pricespy.