I am planning on taking the night train from Prague to Krakow in August, so high travel season. It seems risky to me to just hope there will be an empty sleeper berth. I don't want to sit in coach all night. Has anyone found a reliable way to buy this ticket in advance on the internet? Hopefully without paying a ridiculous markup.
I logged onto the Czech Rail site, expecting to be able to book the night train online. However, I found a message saying that to get fares for an international route it is necessary to call the Contact Centre. Dial 011 + 420 840 112 113. FYI, to get the timetables to appear I had to enter Praha and Cracow.
We took this train about 4 years; we bought the tickets from a travel agency (recommended in the RS guidebook) once we arrived in Prague. We left about 3 days later and was plenty of time to make the reservation.