D
Nonexistent
While almost 95% of undergraduate students chose to live in on-campus housing, the few who do venture outside the Yard are often those who wouldn't ever need to consider the cost of living in an apartment. Apartments around campus are expensive, usually pretty old, and worn out from its previous college residents. For those who find cheaper or at least reasonable housing, it's usually pretty far away from the center of campus, inconvenient, and still more costly than other colleges in the area.