I paid 60 Euros for a night. There is very friendly and helpful English-speaking staff. Good location with easy access to restaurants and tapas bars. If you bring heavy luggages like me, you are suggested not to use the nearest Metro station Santo Domingo, but Callao is more convenient since it has a lift, which is about 150m on foot from the hotel.
Although the hostal is really near to Santo Domingo Metro station, but I still inquired a few people and finally the police showed me the correct direction. Basically addresses in Spain are rarely clear, so, it would be more helpful, if the the name on Booked.net matches the real hostal sign and its indication is clearer.