Hej,
the workshop will be financed by the foundation "Fundacion Zaragoza Ciudad del Conocimiento", what means that the only cost for you will be the materials (that you probably already have).
THE WORKSHOP IS FREE OF CHARGE!
About accommodation in Zaragoza, I think you should just wait for one week when the people at the foundation start to gather applications to the workshop. You could ask them because I don't know much about it.
However, Zaragoza is fairly cheap in every sense. Any hostal will be having quite good quality.
Hasta pronto,
/David