WOW that flickermaster is expensive!
You can build the same sort of thing for under 20 bucks!
(people in the haunted house industry do this all the time)
Just do a search for flickering lights plans. Not getting too technical here, you can do a flickering light either by just wiring a flourescent light starter to a regular light bulb (I haven't tried this -- but supposedly it works -- seems dangerous to me though)
OR
take a photo resistor and wire it in series to a light or group of lights, enclose it in a box that has a flicker bulb (from home depot) in it -- now your regular light bulbs will flicker at the same random rate as the flicker bulb.