Are you sure the display is bad?
I've had two Batman Forever's that the display liked to blank out on because of inconsistencies in the power supply. (Not a solid +5v through the connector as it ages).
There is a fix, and a way to re-wire it. http://www.sternpinball.com/downloads/sb106.pdf
Again, this might not apply to you. Generally this helps the oversize displays that are "blanking out" sporadically.
Just worth a shot before you invest a lot into a new display.
Batman Forever is a really good game. It is certainly worth trying to get fixed.
Pete