we usually eat in food stalls

There are cafe's right on the river if you walk against the traffic. We stumbled upon a great cafe where no one spoke English and was excellent and inexpensive. Locals hung out there, drinking coffee and ate antipasto.

Osteria Numero Uno, all the locals eat there. Just stay away from the main canals and touristy walkways and you'll be fine. Try to find a small café or trattoria in a back alley, the food is cheaper, better, you'll get bigger servings and you don't have to wait for an hour for spaghetti. Plus, you'll be able to have a nice chat with the owner of the restaurant if they've got time. Btw, Italians don't have lunch before 1.30 pm normally, so try to stick to that rule of thumb if you see a place that is crowded.

We ate down a random back alley in Venice and the food wasn't too pricy..Not the greatest meal ever had but still good. Italian food was not good for us on our visit at all..They make better Italian in Croatia than they do in Italy haha.

Walk through the back alleys to the cafes/restaurants where the locals hang out. You may even see families hand making the pasta as we did :)

Definately wander away from the grand canal or shopping areas that tourist frequent. Stroll the alleys where you see laundry about you and you are more likely to find a better place to eat.

wander off into the small allies in venice and stay away from anything near marcus square et al. it's best if you look out for small "osterias" where the locals usually have a snack. they might not speak english there but you can just go in and point at what you want. they often have really good antipasti, stews and "real" italian food. i don't have any addresses i could speficially recommend, i just tend to wander around and "gate crash" the italian places.

I'd rather suggest you choose a small place on the outscirts of the city where you see local people than anything in the centre. It will be cheapper and what is more important you'll have the opportunity of trying how Italians eat, not how they serve food for tourists. Like Nicholas said - try the house wine, it's always a good choice. And do ask what they recommend you at each particular place - they'll be glad to content you with their specialities :) If you want to save some money, order only from the first dishes (primi piatti) - they're usually quite filling-up and twice cheapper then secondi.

Most of the food in the tourist areas is a bit over priced. I would say that most restaurants along the grand canal had good food. Be aware the most the time the portions are much smaller. Also if you like wine, then I recommend ordering the house wine. It is usually quite good and specific to each place.