Maybe I'm one of the few who noticed that the OP didn't want to spend the $120 on Ortlieb if he can help it. I've used a $25 grocery bag pannier for 3 years, still going strong. The plastic bag I put my laptop in when it rains didn't cost me a penny.

For a college student carting laptop and books and bulky things, a pair of grocery bag panniers would rock the party, imho. A pair of rain covers and he's ready for anything.