Ouigo in Spain are having a sale from 19 March with tickets from 9 Euro to their existing destinations, and new destinations of Valladolid, Cuenca and Segovia.
https://www.ouigo.com/es/en
I am sure the devil will be in the detail as they say, but that is the headline.
It is up to the individual whether the limitations of the low cost Ouigo service suit their travel plan or styles.