When buying a property you found buy yourself, never do the deal with the agent of the seller. There are a lot of scams where he can be involved and it is highly recommended to have your own agent checking all the details.
For instance, he should check for you
- the type of building (eg. wooden, reinforced concrete, or mixed structure) which can change the value of the property by several million RUB
- the flat configuration (a change in the plan, not approved by the authorities, will oblige you to put back the flat to the norms and pay a strong penalty)
- the ownership documents, and registration list (not to face major issues when buying and/or reselling the property)
- the health check of the seller(s). If you don’t have the proper documents from a doctor certifying the good mental health of the seller, you have the risk to give back the property upon demand of the previous owner