For an assignment, I was paired up with a professor who also has an administrative role within my college. The assignment was unique to me, with a competitive process to be chosen for the assignment (or put on to a different one). The assignment was to produce some software for the college.
The assignment did not require me to completely finish the software. The assignment has now ended, and the professor has informed me that he expects me to receive a good grade.
Outside of my studies, I make a living doing the same work that was required of the assignment (hence why I took it). The professor has asked to meet me to discuss completing the software to the college's specification. The professor is also the one currently marking the assignment. He has offered me an extremely modest sum of money for this - I would never work for this low rate under any circumstances in my job.
I'm concerned that refusing to work for such a low rate will jeopardise my mark as there is a conflict of interest. I do not have any feelings either way for the college and do not feel that I am obligated to complete the software, other than to appease the professor, and the college is very wealthy and so could afford to pay me a reasonable rate. Furthermore, during the course of the work I will graduate and no longer be a student of the college.
I am looking for advice on how to approach this. Would you suggest that I complete the work for, basically, free? Otherwise, how can I sensitively reject the work without affecting my grade?