You say you are going to the 'cafe' while at school. Are you buying meals there? If you are looking for something that is relatively cheap stop paying for meals at school and make them at home.
As for night time shake. two tablespoons natural PB eating off spoon, casein protein, leucine, and EPA/DHA
Weight gainers are easy. I like muscle juice revolution but I am unsure of the price. Milk is good!