The trial version of Microsoft Works isn't a full version.
For example, it has TRIAL VERSION across every page that you write...
And you can't print what you have written in the trial version.

Pooling the cost is a good idea. I'd still be surprised if he was unable to get it off the university site license... But that being said pooling it is one way of getting it for sure.

An alternative might be to try and pick up a second hand copy of an earlier version (especially since 2008 is out now)