Stadtalm is a small hostel above a restaurant on the hill overlooking Salzburg's old town. We stayed in a small double room with shared bathroom.
The room was pretty basic and small, but it was very cheap at €37 a night including breakfast.
The best thing about staying here was the location. It's a bit of a hike to get to (15mins up stairs and a cute path along the top of the hill) but it was worth it for the amazing views across town.
The shared bathrooms consisted of 2 separate toilets & 2 separate shower rooms (one guys one girls). They were clean and we didn't have to wait to use them as we were the only guests staying there.
I would definetely recommend Stadtalm to anyone looking for cheap accommodation in Salzburg.