Articles rewriting

I need somebody to rewrite health articles. I will provide you articles that will range from 300-500 words. I will need you to rewrite the articles so they they are not duplicate. All articles must be human made, make sense, be high quality and must pass copyscape.com. I am willing to pay $30 for the 50articles. This is just a rewriting task so it should not be difficult. Payment will be made in the end of the project. Plz provide samples with your bid. I need writers who have perfect grammar for this job. If your grammar is not perfect and i find that out afterwards, i will terminate the contract. If your samples are online, it will be preferred. Articles will be provided to only to selected bidders