I just looked, and there's a big difference between the two airports coming from D.C., too. It would end up being something like a $100 difference, counting the cost for a young upstart 😉 to rent a car. I talked to my parents (who are paying for much of my interview expenses), and their thoughts were that it would be too much extra stress to be worth the money -- my first time renting a car, possibly getting lost, driving almost 4 hours in the winter w/possible bad weather, worrying about getting it back and being on time for the flight, etc. I don't have a lot of extra time to get back after the interview, since I have class at 8 AM on January 25.