Yes, DNN will be just fine for this use.  We host/service numerous mid-small size company websites that have had the same frustrations.  Clients have gotten tired of paying an hourly rate to make simple changes - so most are switching over.

I guess the first thing you have to figure out is if you are going to be installing & learning DNN yourself, or paying someone to do the work for you.  I'm not sure of your expertise in the field, but most likely you are going to spend a week or so figuring out how to Install, Skin, and maintain the site.  For a couple of static HTML pages you might be better off paying someone for a couple hours of work to make the simple conversion and you will be set up.

If you or your friend would like to try out an example site using DNN, let me know and I can set up something similar to what he would be using with his site.

-James