The box of MREs is about $75, you will eat them primarily during the last 3 days in the field or you could bring your own stuff. During the first 3 days of ATLS you will be able to eat breakfast at the DFAC & buy coffee/snacks in the canteen in the building where the classes are held. Some of the ATLS classes would pool money to buy coffee & bagels in the morning & pizza or subs at lunch. I would recommend bringing an additional $40 in small bills to cover the extras, no one ever has change.