Well, you wrote "budget" and meant per day, while I thought you meant "tour budget", excluding travel and accomodation/food per destination. Anyway, it is very difficult to say what is cheap and what is expensive as no hotel names are given, no description of the restaurants, etc. They may be feeding you (for lunch) with a single pasta serving or with a full 3-4 italian meal. Anyway, a few years back we (i.e. wife + me) toured for one month South America for 2500 € for two (yes!), which included all food, hotels, entrance fees, e few car rentals and trains but not air fares (we were criss-crossing the southern part of the continent from Ushuaia all the way north to Lima); if air travel was included (w/o the TATLs), the total cost for two was much less than 4000€. When we came home I checked the cost of organized tours. The cheapest I found was 50% more expensive for two weeks! Unfortunately, you'll have to decide based on what they write in their offers, which is often rather far away from the real thing.