Cost of living in Bridgeport, Connecticut (United States) is 50% more expensive than in Zaragoza (Spain)
This comparison is lacking data. It provides a decent comparison, but it is not yet reliable. It is based on 240 prices entered by 32 different people.
For example, you would need at least €3,907 ($4,810) in Bridgeport, Connecticut to maintain the same standard of living that you can have with €2,600 in Zaragoza.