Apartments: 600 share a living room/800 share a bedroom/ 1000+ enjoy your own room
Merto: around $2 per ride from Arlington to school. About $50 per month
Food&Grocery: $200 to $400
Car: ok...here is the good news.. u do NOT need a car in DC..
Shopping: Eeeeee... it depends...
so a $1500 per month budget sounds reasonable to me...