Developing 400 word content for ~150 cosmetic surg micro sites

We possess nearly 150 (probably more as we are currently taking inventory) URL domains and are in the process of building mini-sites for each domain by a sole cosmetic surgery service provider. The provder is attempting to make public aware of different options available at our facilities as well as increase the SEO value of each as well as the primary site. Since the latest Google release (Penguin), we want to avoid duplicate content at all costs in order maximize SEO and minimize identical content. We want to avoid spammy looking content and content that doesn't look natural or read well. We need someone to write / re-write exisiting material available widely in the net and the provider's existing 5 websites and translate it for use on all of our landing pages for the intended mini sites. We need about 400 words of content for each site stressing some of the obvious keywords such as the primary procedure, before after photos, costs, etc. A lot of this is already written but this needs to be re-written so as to avoid duplicate content. If you remain interested, we are putting this project out to bid and we would like to know what your billing requests would be for this (approximately 150-200 mini sites with original content of 400 words each). We are reviewing all responses Requirements: - Must be by a NATIVE ENGLISH writer. Responses that are poorly written will be viewed as indication of work quality. - We must see examples of your work before we accept your offer. - Must be excellent at spelling and grammar. (I will not pay until the content is free from grammar and spelling mistakes.) - All work must be totally original. We will check this. - Must include the keywords relevant to the URL - Most landing pages need to be re-written, in these cases you will be required to keep a similar keyword density. - In the cases where you will be writing from scratch we will guide you in terms of the keywords. - There are existing websites providing comparable services which we can discuss to use for comparitive purposes once the project has been granted. - I will own the copyright for all the content once I have paid you. You cannot re-use or sell any of the content for any reason