Need Professional Writer - Urgent

Hi, I need a professional content writer or a team, who has enough experience in this field and also able to manage with 10-15 articles a day. My budget is, 1)300 words-0.8$ 2)350-400 words-1$ 3)400-450 words-1.25$ 4)450-500 words-1.5$ 5)500-600 words-1.75$ I have no. of sites, and a person should be able to write on any given topic, with proper use of keywords. Also, use of perfect English and grammar is necessary for the task. Please show me any of your past work. Please do not bid if you can not submit 10 articles a day. Happy Bidding :)