"If there is research involved, each sentence or paragraph could easily take an entire day." That's not how writers or the publishing business works. Presuming you made real-world top dollar, $2.00 a word, your $12,000 dollar article would bring you $40 an hour. Odds are you'll actually make a buck a word, so you're already down to $20 an hour. You can dream of a world where writers make 100K a month from projects like this, but with 30 years in the business I don't know anyone even close to that.