This is half an hour of programming service.
Priority - if customer want faster turnaround then it means that we must work harder, therefore cost increment. As we plan out work few days in advance a higher priority means frequently to work longer days.
Copyrights means that all algorithms must be yours, not ours. Therefore we cannot reuse the code we already have and the customer must define all functionality of the EA/indicator/script. This is much more work than just reuse our standard code blocks. Therefore the higher price per hour.
NDA means that we cannot use subcontractors for the project, therefore the hourly rate increases.