The current office 365 solution for me works out to be about $2 AUD a month per device.

Considering no 'upfront' cost that isn't really too bad for me, and I have no problems paying for tools I actually use to get work done.

If people want to edit Office documents using non-Office software there are plenty of free alternatives.

The fact that Microsoft is the only company able to do this without formatting errors is value that I think is worth the fee.