Although I have no first-hand experience with them, I've found their prices a bit on the steep side.
I took my hi-res images to a local printshop, explained exactly what I planned to do with them, and how I expected it to look. They worked with me to create the Marquee on a back-lit material, with a 3/4" border around the edges for mounting. They did the side art (x2) and even put the marquee onto the Plexi for me for free.
In the end, the price was about half of what I'd seen at mamemarquees. Again, I'm not saying they are not good, just that I found a local option that was cheaper.