in what currency?
depends on where do you live
I know Vienna is pretty cheap but Paris on the other hand is very expensive even if you arent very pickyIn Rome yopu could visit their Social centres or Case occupate
http://www.informa-azione.info/contatti_case_occupate_centri_documentazione
For anywhere else, try finding a roommate on a http://www.hospitalityclub.org/
I think its a good for a start
I guess he asked for portugal, I have been there... rent is something like 250/300 euros for a nice room in the city with all the most basic things included (water, internet, penis, etc).