I'll echo Melissa and Charlie and recommend an opensource option
plus various GAFE components. Drupal and Joomla are very solid. I'd add
WordPress to the mix. Here's the short framework of what we've done:
- WordPress MultiSite install. Each school in our district is a site. Teachers can get their own site as well.
- Purchased a well maintained (and great looking) theme.
- Added some key plugins like site backups, directories, Google Login (or AD login), Gravity Forms for more robust forms.
You do need to put a bit of time into setup and learning the system. Some money is required (for hosting - although many districts have servers available), theme, etc. But it really is a platform that functions as a kitchen sink. There's a plugin for every possible idea.
IMO, Google Sites leaves much to be desired when it comes to aesthetics (when are they going to upgrade it to match their
Material Design philosophy?). Design matters, especially when it's the public face of your district.