We publish what each level of service includes, but not a per-screen price, and that is deliberate rather than evasive. The honest number depends on how many screens, across how many sites, how often the content changes, whether we hold spares for you, and how far an engineer has to travel when something fails.
A single advertised price would either be so high it puts off a small customer or so low that a national network gets a different number on the first call. Ask us and we will price your actual network, in writing, with the hardware, the licensing and the management as separate lines so you can see what each part costs.