Web content Writer wanted

I am looking for a writer to write articles on specific topics. These articles will usually consist of 250-300 words (3 to 4 short paragraphs). I currently require 25 of these short articles. Articles will have to be written with search engines in mind. Guidance will be given on this once a writer/s have been selected. I am looking to pay $4 per article or $100 for all articles. Samples of past work will be required