We are using a writer out of Phillipines that is doing a great job at 3 articles a day averaging 500-600 words an article. The articles are of above average and good. Agree with old_expat on the his comment as we do the foot work and give them links to content to read and write about as well as the subject matter for the 3 articles a day costing 1500.00 a month.
This is about 75 articles a month that are added to our sites or 20-25 per article. They have holidays as well so there are some months when he doesn't meet the 15 articles a week.