Translation of sardine in Spanish

We drove to the hotel Rex where we made reservations in advance. However, once there, two American guys told us that they had a voucher from a travel agent and the price was like half of it.
I am learning Spanish in university but I also have to improve it for private reasons. Do you have any suggestions. It is giving me a hard time lately as it is difficult. I need to be very patient.
We asked for the price and were surprised to hear it: A hundred dollars a night. We were actually happy to hear the high price because we knew that if we would not find anything else there was still a good place to stay in.