I am a grader for USA(J)MO. Let M be the amount of money that I earn from this (pre-tax). I will estimate the hours spent H as follows:
For each problem P I grade, using a period of uninterrupted grading near the middle of my grading experience for that problem, I will estimate R_P, the amount of papers that I grade per hour in an ideal setting. These will be rounded to the nearest tenth.
I will sum the amount of papers I graded divided by R_P over all problems P.
The reason that I am using this procedure is that I often grade in non-ideal conditions (e.g. while eating, while in class, etc.) which decrease the amount of papers I grade per hour, and it would be unfair to weight this time equally.
Finally, I will add 1/6 hour (10 minutes) per conflict. (These occur when I assign a different score from another grader, and we need to agree on a score.)
This market resolves YES if M >= 25*H. Otherwise, it resolves NO.
After USAMO scores are released, I will release the the set of all problems I graded, and for each problem the value R_P, the amount of papers I graded, and the amount of conflicts I had.