Krasnodar. Flats for rent starting from 10k r/pm which was around $200 back then. 5000 p sounds very cheap, especially in a new building.
These I've seen myself on Avito and not much actually changed https://www.avito.ru/krasnodar/nedvizhimost?cd=1
Can't speak about median salary as I wasn't doing a proper survey - just talking to people. Those I talked to were either self-employed or on paid office jobs and made 15-20k r/pm.