To get his college degree in four years, LeRoy needs to take 30 credit hours per year, which will cost him $15,000 to cover tuition, fees, and textbooks. His annual cost of housing is $5,000, and his cost of food is $2,700 per year. If LeRoy does not go to college, his parents will let him live at home for free, and he will spend $1,000 less on food. The rest of his expenses won't depend on whether he goes to college. LeRoy's best alternative to college is a job that pays $30,000 per year. How much will LeRoy's college degree cost him?