If you can't write 10 or more pages per day, you basically can't make a living at this. To paraphrase freelancewriter, what seems daunting or impossible for a student is all in a day's work for someone who does this for a living. Two 2,000-word essays is well within reach for all writers that I know, myself included, especially if done to American undergraduate standard. British work is known to be a different animal, and thus the business model there is usually to charge far more and allow for numerous revisions. I personally refuse almost all British work.
When I was in college, a 10-pg paper was something I dreaded and it hung over my head like a dark cloud all term, exactly the way it does for allof my clients now. I could never have imagined that someday I'd be writing the equivalent of 1or 2 10-pg papers just about every working day (or night) of my life. When it come to UK work, I don't necessarily decline it, but I'm definitely much more careful about what projects I can take safely and I do routinely pass on many assignments that I'd do without hesitation for US clients.