I will be in the Czech Republic later this month and planned on travelling from Prague to Krakow by overnight train. I went to polrail.com and they are quoting 876pln for 2 persons in a sleeper. That is over 200 Euros or about $270 U.S. Surely it is not that expensive is it? Is there anyway to get a cheaper ticket?
Travel in the daytime on intercity trains. Night trains, unless you are committed to the experience can bean uncomfortable way to travel. We have been on three, all over fifteen hours and found they stop at every little station along the track. Sometimes we got to sleep.
Here is a great website for train prices and processes. http://www.seat61.com Hope it helps.
Are you willing to share a 4-bunk couchette with two other people? If so, the Czech Rail site shows a total fare of 1782 CZK ($95 US) for two people.
Have you tried this site? https://www.cd.cz/eshop/default.aspx It is showing tickets in a sleeper for two for less.