We stayed at G Guest House located in Itaewon, Seoul. A mixed 4 bedroom dorm will cost you 26,381KRW/ $29.55AUD p/p/ p/n, this includes breakfast.
You have the choice of cereal, toast, eggs, tea, coffee and juice. The rooms are spacious, with very comfy beds and a shared bathroom. Lockers were also provided for valuables. There was also very good heating throughout the hostel, it does get very cold especially of a night time, they even had heated floors! We had trouble booking on HostelBookers (it said they were full) so we emailed them directly firstname.lastname@example.org and managed to book a room through them.
This place is fantastic, it is close to all sights, shops, restaurants and bars in Itaewon, it has a very social atmosphere with a rooftop and a common area. But most of all the staff are very friendly and extremely helpful.