I have outsourced article writing overseas and have had good success. Check onlinejobs.ph This is a website specifically for outsourcing jobs to people living in the Philippines. If you post a job there, you will get tons of applicants.
Most write okay, but some write really well. I would say that about 5% of the applicants write well enough that the average American reader could not tell the difference. The key is to read their resume, and then ask the most promising candidates to write an article specifically for you. I used the quality of those articles to make my final selections.
I hope that helps!