The Lebanese Kitchen is a favorite of Fuller Seminary students who are shopping at the Christian book store (Archives) next door. I wouldn't call it dirt cheap - maybe more like $8 per person, but it is a fantastic value, with good, authentic, healthy food.
They make wonderful falafels and kebabs, and surprisingly decent salads. Definitely go with any recommended specials.
It's not the most charming place, but casual and comfortable. You know you are in a family place and the food tastes like you're in a friend's home.