Using the coax that's already in place, you could get an old Channel Plus/Channel Vision modulator (use a reputable brand) for next to nothing off of ebay and just create a channel for the send. It is not HD and there are better ways to do this, but even an old modulator should easily have enough signal strength to push three TVs and would not require any additional wire to be pulled. The composite/baseband video, that is allegedly being used now, would be better. But the run out to the one monitor and then passively split to the other monitor right next to it, would not work well. In my experience, most video does not like to be passively split. Another line directly to the second monitor, would make a proper video distribution amp a better solution.
