(I’m not sure if this should be in IMHO; if so, many apologies!).
This is actually for a friend of mine. He asked me this and I really don’t have any idea.
We’re in the Detroit area and he was contacted recently about doing some contract writing for a business that produces advertising pamphlets (for various companies); he’d be writing the text in the pamphlets. He needs to give a quote regarding the four types of contact jobs he could get. The jobs could be 12, 16, 20 or 24 pages. From what he said, a 16 page document would be about 20,000 words since much of the space is taken up by graphics, headings, etc. Each page of a document is a different company.
From my friend:
He doesn’t have much experience in the field. He graduated uni this past May with a BS in Humanities (which at our uni is basically English, with a broad range of electives, etc). I’m saying this because I don’t know whether or not this will impact what he should charge (as opposed to if he had, say, 10 years experience doing contract writing).
If Dopers are able to help him out, he said he’d be so happy he’d probably join here. 
He’s a smart guy, and would be a great addition to the bunch, so hopefully people can help him out. 