Hello mate,
No writer in the world who have grammarly premium will write 1000 words for $1.4. I'm sorry to break it to you, but this is the sad fact. It is because writers who have been freelancing for a substantial time are the only ones who have grammarly premium. And these writers are seasoned enough to know that they can easily charge $5 per 500 words with their premium tools.
I say this because I have been in the freelancing industry for a straight 10 years. I have seen and learned enough about it to know this for a sure fact. If you want me on board, I will be using copyscape and grammarly premium. But I will chrage $5 per 500 words. I doubt that's a possibility, but sometimes the impossible happens so I'm always up to try my luck!
Thank you!
Yours,
Nayab