This is our house in Rábade, Lugo. When we bought it several years ago, it was a complete ruin; many properties in rural Galicia are in a similar state.
It took twenty months, but we did all the work on the house ourselves, so we know exactly how much work goes into a restoration project, how much it really costs, how long it takes and how to do it.
Galician houses were made thought-out by yesterday people, people that frecuently shared his knowledge around the fire (the lareira) after a day of hard work slowly biting the granite stone lintels for making their houses tougher and more beautiful.
Rural homes in Spain are not necessarily costly to restore, you need: good control, good guidance and guaranteed prices.