Cost of living in Kaliningrad (Russia) is 53% cheaper than in Zaragoza (Spain)
This comparison is lacking data. It provides a decent comparison, but it is not yet reliable. It is based on 257 prices entered by 28 different people.
For example, to keep the same standard of living that would require €2,700 in Zaragoza you would need to make just about €1,270 (руб 96,329) in Kaliningrad.