Article Writing

I am looking for someone who is able to write 50 website articles for $1.50 per article. The articles are on varied subjects, for a start, articles should focus on internet marketing or SEO related topics. The articles should be well-written and typo error free. Each article should contain 450-550 words and the content should contain the same 10 essential key words relating to the title. The writer can research from books, or internet but articles need to be creative and original and not copied from elsewhere. I am looking at long term with this writer. Future topics would involve music marketing, beauty marketing, etc. I would appreciate it if the writer could send me some samples of his works to ascertain his skills. Thanks