Hello. I am currently involved with a project that involves writing 500 word biography on celebrities. If you want, I can provide you a sample. Also, I have written articles on android applications, technical companies and health products before. The link for which will be provided on request.
Although, for 800 word articles complete with high quality English and completely proofread, I would charge $7 minimum. If you agree, I assure you of high quality articles delivered within required timeframe.