Cost of living in Modesto, California (United States) is 10% more expensive than in Arezzo (Italy)
This comparison is lacking data. It provides a decent comparison, but it is not yet reliable. It is based on 264 prices entered by 17 different people.
For example, you would need at least €2,633 ($2,967) in Modesto, California to maintain the same standard of living that you can have with €2,400 in Arezzo.