Upvote:1
Usually, in Italy you can have a very nice meal in range of prices going from 20 Euros for person up to 100 (some top restaurants can be even more expensive), beverages included.
Also in the cheapest places you usually find good quality food (it's difficult to find bad food in Italy).
Regarding your family difficult tastes, usually you can find almost everywhere simple dishes like pasta or meat that could be a good choice for them.
Upvote:3
Impossible to tell without knowing your family and their preferences and dietary requirements. I'd suggest finding websites of restaurants in the areas where you'd be residing and check their menus and prices. If you are not opposed to cooking, find what local grocery chains are available. This should give you some ballpark estimate of what kind of prices you should be expecting. I'm sorry if I'm not specific enough, but your question is just too general.