We’ve sold a few – not cheap looking at £1500 – £4000 outlay for a 50" free standing unit depending on what you want to do. Top end units are connected via Wi-Fi or even SIM card so you can change or update adverts without visiting site, plus get status reports, this is a great upsale service that you can provide for ongoing revenue. Smaller presentation screens are a lot less!!
And no, domestic ‘smart’ TV’s are not suitable, as they are not rated to run 24/7….. yes I’ve had a customer ask this before.
Artwork is pretty easy for basics flat images just a standard Jpeg etc, you can then progress to simply photoshop timeline (GIF, AVI), and if you really get into it create using something like Adobe premier pro & After Effects for the really coooool video stuff (MP4 etc) (tip: you can buy a huge amount of premade files now from the likes of shutterstock etc), all the units have some form of Android media player software running making it very easy to add files to the internal harddrive, with control on how it plays back. On power loss, they just reboot and play.