From my own experience, many of the property buyers I talked to wanted to buy a home by the sea, especially if it was for temporary residence. Such inquiries are from immigrants who buy a "dacha by the sea". They are not interested in the center of the country, they need a coastal zone, peace and quiet.
It is worth focusing on ecological zones, away from noisy cities. There are no clear rules for location, the situation on the real estate market can change at any time. In short, about the general patterns, then it is worth adhering to regions with developed infrastructure and at the same time it is not worth buying the most modern and expensive objects now for subsequent sale. In advance, I would advise you to analyze the buying activity of a particular place where you are going to buy a house or apartment.
And another important point. If you think that somehow you want to combine the purchase and sale of real estate with obtaining a residence permit, permanent residence, citizenship, then I want to warn against a risky step. Since it is necessary to take into account the footage per person, so that later, when requesting a residence, the realtors would not refuse you and the realtors, spreading their hands, said that they did not know about these nuances.
Only a professional who is well versed in liquidity, knows the laws of the country, has enough time to monitor price dynamics can buy and then sell objects profitably.
Therefore, decide for yourself where to buy in order to sell, if, of course, you plan. My agency is always at your service.