If you in the center you can use Market Place — it is good and not so expensive cafe with different food, or you can use #Pirogovii dvorik# or #teremok# — this is cafes with nice local food also not expensive and each of them have sets. For transport you can rent a bike (blue stations) and public transport. We have some special tickets for the tourists.
We got information about prices in Saint Petersburg on food in cafes and restaurants, products in supermarkets, accommodation rental, real estate and transportation costs based on the data of 256 people.
We analyzed the average prices in Saint Petersburg and calculated that one day in city will cost you 5470 Russian rubles.