In many parts of Italy a whole pizza is just €5 and they are great (obviously). As has already been said, avoid the main tourist places as these are both expensive - they'll charge you between €2 and €5 just to sit down and the food isn't so great.
Finding non-tourist places to eat can be a bit of a struggle since Italy is overwhelmed with tourists but we had some luck with http://www.taxigourmet.com/ about 8 years ago
Just arrived back from Italy. Be very careful in touristy areas, I had my purse nicked with all cards n cash!
We ate in naples and sorrento as well as other small towns. We paid for 2 persons, breakfast:9€ for 2 Americanos and 2 ring doughnuts or similar. For lunch we went to either supermarket or small store and bought a roll and slices of ham and Brie which came to about 5€ and a bottle of cheapy wine for 1.50€. We bought a pack of plastic cups, make sure you take a bottle opener. Dinner: pasta dish, approx 7€ per person, steak approx 13€ per person. This doesn't include veg side dishes which are approx 4€ ea. ask for house wine in restaurants, approx 12€ although we had a bottle in one restaurant for 2€ :). You can drink tap water if you want to. Have a great time, hope this is helpful and most of all BE CAREFUL! about 8 years ago
For breakfast I can spend about 1.30€ for a coffee, 1-2€ for a brioche at a local cafe
For dinner and lunch I can find food for around 5-10€ for each meal
Drinks (alcoholic or non) about 2€
For shopping at the market I spend about 30-50€ and that will last me for about a week or two feeding myself and my friend
For wine, I can pay about 2€ in the market for a liter
Depending on where you are in Italy, wine will be more expensive at a resturant in a bigger city, I have found the cost to be about 2€ for a glass in Vicenza, but, if I go to Venezia or Milano, it really all depends, say, your near the Duomo, it will be more expensive, last night I went with a new friend in Milano to this winery and the cost for 1 liter was under 3€. For dinner that night we went to a cute little cafe that was serving all you can eat for 9€ and that included your drink for the night.
So it honestly is in each persons perspective, I am going to be in Italy for a while and I am on a tight budget, so I look for affordability when eating out. about 8 years ago