Cost of living in Havana (Cuba) is 18% 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 365 prices entered by 28 different people.
For example, you would need at least €3,433 (4,209 CUC) in Havana to maintain the same standard of living that you can have with €2,900 in Zaragoza.