Cost of living in Havana (Cuba) is 19% 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 406 prices entered by 32 different people.
For example, you would need at least €3,331 (3,894 CUC) in Havana to maintain the same standard of living that you can have with €2,800 in Zaragoza.