Cost of living in Kazan' (Russia) is 7% more expensive than in Łódź (Poland)
This comparison has some inconsistent or sparse data. It already provides a reliable comparison but it is not bullet-proof. It is based on 409 prices entered by 34 different people.
For example, you would need at least 7,893 zł (руб 139,900) in Kazan' to maintain the same standard of living that you can have with 7,400 zł in Łódź.