You could have done full-assessment with NZQA withour Pre-assessment.
If you visit qualifications section on immi.gov.nz, you will find that 4 years Bachelors and 2 years Master from India will fetch 60 points.
As you said, you have MS from USA. I guess you have four year Bachelor in Engineering.
I am pretty sure if you do full assessment, they will nominate you at scale 9 (60 points).
I guess you should go with full assessment, it is NZ$746. I know money is important but for getting something you have to bear.
This my suggestion, rest up to you.
Please ignore mistakes and no personal offences.
Regards.