I work for an international printing company. We do trade show graphics for Cisco, Microsoft, and other large companies as well as blueprints, vehicle wraps, and all kinds of other stuff. We don't specialize in arcade graphics like other vendors mentioned, but we can print just about anything on literally just about anything. We have equipment to direct print on just about any substrate (including plexi and other sheet goods), as well as engraving and CNC cutting. The CNC mill is sitting next to me in my office, as I built it and am the only one that knows how to operate it. If anyone has anything out of the ordinary they would like to have done, I can more than likely arrange it. I can get marques reverse printed directly onto the back of plexi cut to specified size if anyone would like to give it a shot. Not sure about how "black" the blacks would be when backlit, as I've only ever seen the printed plexi used with wall standoffs, but no worries about it peeling.
Also, we usually come in less than half the price of Kinkos or Fast Signs, although turnaround time may be a bit longer depending on which office has the equipment to complete the order. We have aqueous, solvent, and latex large format color printers local to me, and can get just about any media that's made.
We have offices all over the US as well as some in Canada, the UK, China, and India. Our website is
http://www.e-arc.com.
I'm part of the IT and service department, so I don't do the printing myself, but I can help coordinate if anyone is interested in something other than basic printed self adhesive vinyl. For that you can contact the office closest to you for pricing. Production capabilities vary from one office to the next, but if one office doesn't have the equipment in house, they will have the nearest office that does handle the production.
Sorry, don't mean to sound like an advertisement. I just have some interesting ideas for things other than standard printed vinyl that make use of some of the unique capabilities we have....
---Edit---
After speaking with my production manager, we can do 3mil polycarb laminated 3M 5yr permanent adhesive vinyl overlays for somewhere in the neighborhood of $7-$9 per sqft, depending on order size and such (at least at my office). If I did the math correctly, GoG is charging somewhere in the neighborhood of $22 per sqft....