Need Article Writer

Looking for a good writer to provide twenty (20) 400-500 word articles or blog post about graphing calculators. The articles should be written in an informative or "how to" format. I will provide rough titles (to provide direction...you can re-write title as needed) and keywords phrases to be included. You must have excellent American English and grammar skills. The articles must be 100% unique and original (pass copyscape, ect.). Absolutely no spun articles. I retain all rights to the articles. This project is for 20 articles to start, but I will need an ongoing supply. Payment for future work will increase with strong writing skills and a good working relationship. Payment is for the completed and approved article...I will pay after each approved article if preferred. The budget is $30.