I collect arcade units and parts. In fact, I am looking for joysticks and stuff on my trade list right now.
I have about 20 marquee signs (plastic and glass). I want to make a quick point about buying them. It is better to do it in person rather than ebay, but either way, you must look for scratches.
Hold the sign up to the light because once it is in your machine the light will shine through and be very annoying. The coating on the back is very easy to scratch. I imagine that if it is not packed well it will easily get scratchs in the mail. After holding it up to light, lay it flat and look at the back for imperfections.
You'll regret it if you don't.