How can end users create a variety of compelling content for private networks without breaking the bank?”
In many private networks (or corporate networks), there are already professional designers on staff that are creating content for websites, print media, news and information media, video media, brochures, catalogs and magazines. These in-house professionals should be approached to discuss the possibility of using existing content design elements that have already been created for various projects that can be also tasked for digital signage. Be sure to provide any design and branding criteria (i.e. 1920 X 1080, RGB, 300 dpi, JPEG; official hex color codes) that your digital signage might require. You might even find a new friend, in that now their lovely designs will be seen even more prominently across a very different form of media!
You could also reach out to the local college or university creative design programs to see if the faculty knows of students looking for required semester design projects or even internships! Also, some campus website designers or other content designers are permitted to “moonlight” and have their own private design practices.