20 $5 articles will get you much better results than 100 articles that are stolen from other websites and rewritten in poor English (which is what paying $1/article will get you).
I note that you have not asked for quality articles, just that they must be in English and make sense...If that is your only requirement, go to odesk. There are plenty of cheap writers on there that will deliver average articles that just make sense....And some writers on there that are very good but much more expensive.