I can't answer your first question about loans, but I put myself through grad school by working full-time and taking 1-2 classes a semester. Took longer to get my degree, but at least I don't have any student loans to pay back now. Many employers (both in academia and industry - I've had both over the years) have pretty good tuition reimbursement packages included in your benefits which help to defray at least part of the cost of classes.