~$50 (server hosting) + $350 (10x Raspberry Pis) = $400. Compare that to proprietary software which would cost $2400+ annually in subscription fees.

“Xibo is a highly reliable, economical, web-based application/platform for distributing text and graphics content to TV display signage screens.” Software Advice

Not all open source projects are created equal. Some have been abandoned; others have thriving communities. Here are the current market leaders: