You can book for 1€ a bed in a 8 dorm in Hostel Gen in Barcelona. The offer lasts for 24h, first come first served, from 18/03/2014 1pm GMT - 19/03/2014 1pm GMT. you can find the details here:
http://generatorhostels.com/en/hot-d...eds-barcelona/ . Valid for stays until 18/03/2015, max 7 nights. Enjoy!