Sir,
Regarding my work, I will be happy when you praise the same. I can assure you of good quality and complete satisfaction.
Most of terms you have already decided. But, I must tell you that I need US $ 1 per article. The words of article as you mentioned would be approx. 500.
Further, since you are not ready for mile stone, I will need payment promptness from your side. The same should not be delayed.
Regards
Goutam Prasad