Cost of living in Orsk (Russia) is 46% more expensive than in Zrenjanin (Serbia)
This comparison is lacking data. It provides a decent comparison, but it is not yet reliable. It is based on 38 prices entered by less than 5 different people.
For example, you would need at least 112,245 Дин. (руб 66,199) in Orsk to maintain the same standard of living that you can have with 77,000 Дин. in Zrenjanin.