Is it safe to rent Odessa apartment?

If you arrive to Odessa by train or by plane, you can see people with the tablets and advertisings that read something like “new apartments in Odessa for rent by sea” or “Odessa flat from owner”. In some cases owners meet tourists, but lately a lot of ads can be found on Internet sites and numerous advertising boards. Surely, such options seem to be the cheaper than stay in a regular Odessa hotel. Yes, it is really cheap, but in many (if not all) cases low price inevitably means low quality. And in fact it can happen that the apartment looks different from what was described: old furniture, obsolete equipment, no air-conditioning, etc. Besides, there is a lot of cases when gusts of the city rented apartment from a cheat who did not actually owned it, and soon were kicked off from flat and had look for another place to stay.