In a search for something else, I got hooked into a website for signsrus and clicked on something which brought up a pdf pricing file. It's a very good guide and well worth a look. It's geared towards telling customers how much things cost. It starts with base, one color prices and then shows how much it costs to add 2 colors, 3 colors, logos, etc. The information is for aluminum signs as well as banners. It also has some good verbage on telling customers what types of files they need to provide and what works best.
Worth a look : http://www.signsrus.info/catalog/sec...um%20Signs.pdf