The best thing I know is to find tasty food out which does not burn the wallet. For some days ago we went to Babel Deli, the place is perfect lunch or dinner. At lunch time there is major crowed and it is not a good idea go there at 12, either little earlier or later than normal lunch hour. A plate of Meze cost under 100 SEK, which means a student can eat there and feel good, without worries for the economy.
This is a meze plate with mutton, chicken, and much other tasty things. The food is really tasty and fast to get. However, the open hours are a bit limited, closing at 8 pm. They have to two places one on Kungstensgatan 33 (close on Sundays) and Långholmsgatan 27 (open on Sundays too). A place must to go for good food and price.