At the University of Oregon grad students are paid a minimum rate of $24 per hour plus full tuition, fees, and health insurance. They are limited to .49 FTE though. Overhead pays for facilities rent, computers, and payroll plus administrative costs like grant proposals, human subjects regulations and tracking adherence to all of the federal regulations on grants. 15% wouldn’t even cover the facilities (electrical costs, equipment maintenance, etc.) The Principal Investigators salaries are usually the highest expense, at .20 FTE for someone who can make upwards of $150,000 a year not including retirement, health insurance, etc.