Its not a few thousand euros, its a significant amount, and you are limited in what you can do with the house during and after the renovations due to regulations to protect historic places or the local communities, not to mention the building code. And when you are done with everything, you end up having to live in a very remote location, away from most services and amenities - leaving aside modern ones - in remote rural regions that are generally high mountainous areas with scorching sun and freezing wind in your face at the same time every day with frequent weather changes during the day and significant fluctuations every season.

There is a reason why these areas are depopulating: People used to have to live in these remote mountainous locations to survive. But as cities and more comfortable regions became able to support large populations, people started moving to these cities and regions and leaving the hard mountainous village lives behind. Its not an easy life, especially for people who are used to modern society. Its not something that that can be romanticized either.

So the 1 euro houses are an internet fad/myth at the moment.