proofreading / reviewing - only for (UK, US) native speakers of English

We are looking for UK- and US-based native speakers of English to proofread / review large volumes of materials in variety of subjects, such as medicine / pharma, technology and IT, law and business, as well as literature / fiction / non-fiction. Strong professional background and previous experience in providing similar services are required. Please be aware of the definition of native speaker: <<A "native speaker of English" refers to someone who has learned and used English from early childhood. It does not necessarily mean that it is the speaker's only language, but it means it is and has been the primary means of concept formation and communication. It means having lived in a truly English-speaking culture during one's formative years, so that English has been absorbed effortlessly as by osmosis. One can have been born and grown up in a country that lists English as one of its official languages and not be a "native" speaker. For example, Canadians from Quebec cannot automatically be considered native English speakers even though many speak English quite well; they were brought up speaking French as a first language and think in French. But the rest of Canada does largely consist of native speakers of English. Speaking "like a native" of any language means more than just knowing vocabulary and grammar. Many educated foreign speakers speak better formal English than, say, many Americans or British or Australians. But formal English is only one aspect of the language. Knowing instantly what slang means, what cultural references mean, how to reduce syntax to a bare minimum and still convey precise meaning — all these things, and more, are what constitute native speech.>> We regularly provide texts that are either written by non-native speakers of English or translated - they usually require "final native touch". The desired rates would be close to 50% of the prevailing rate for article writing on Freelancer platform - currently $0.35 - $0.50 per 500 words page. Please quote for 100 pages (50,000 words). Please note that some short samples will be required. Please place your bid ONLY if you fully meet the criteria and if you agree with all terms and conditions.