Unfortunately, the cost for the kit is rather steep, at $36.75 each (or $22.25 in volume.) Part of the expense is that this is an interactive kit with an IR sensor per pixel.
Adafruit has a similar module that's a 16-LED display for $17.50, or $14 in volume, but that's still nearly a buck a pixel!
So I was curious how much it would cost to use commodity components to achieve the same effect. It looks like you can get a 1024x768 full-color flat screen for about $150. If you can drive one from a Raspberry Pi the compute power costs just $35, so that's just $0.00023 per pixel. Operational costs might be somewhat more expensive--- and video walls that minimize mullion seem to command a premium. But there's a lot of headroom there.
For example, the 24" display I'm using now has about a half-inch bezel. It's 22" wide by 17.2" tall according to the specs. So if I used half-inch "cells" with inch separation I can fit 15x11 pixels on the display and accommodate the bezel width. And anything less than $450 per monitor would still put me below the cost of the EMS kit--- it looks like similar-sized TVs are available from $200+.