Dear Sir,
First off, thank you for the bid invitation, I really appreciate it. My rate per 500 words is around $4, as I normally write for about $0.8/100 words. However, if the assignment is bulky and for the long term, we could negotiate a price that would be suitable for us both. I could provide somewhere around 2500-3000 words a day without any issues and if further work is required I can occasionally write more than that. I could also provide you with samples of my most current work, should you choose to contact me for further query.
Looking forward to hearing from you,
Kindest regards,
Georgi Georgiev