i stayed 5 nights in Mom guesthouse, in female dormitory. i've met a good host here~!! i'm sure you don't want to miss this nice place that comes with a friendly price.
it's very near to Haeundae Beach, i went there everyday, the beach is amazing even in winter~ also transport is very convenient, bus stops is just 2-3 minutes walk. while Haeundae Station is about 7minutes walking distance. also, there is a contemporary photo gallery in the near opposite too.