I am planning a trip to Eastern Europe in early June. I was planning on taking the over night trains from Budapest to Krakow and from Krakow to Prague. I presume that there are sleeping berths available. It seems that it is cheaper to buy tickets once you arrive than to book them in advance on a website. Has anyone had any problems getting tickets for a berth on those trains a few days in advance in that early part of June?
Popular night trains can sell out weeks in advance. You can book both trains by phoning the German Rail call centre. Dial your country's international access code + 49 (country code for Germany) + (0)180 5 99 66 33. Omit the initial zero in parentheses. It's only used for calls originating in Germany. You'll probably get a recorded message in German. Sorry, I don't know exactly what you'll need to do to be connected with someone who speaks English.
Tim's spot on. About the only time you will hear people on this site saying "book in advance" 100pct is for night trains. They can book up (especially the sleeping berths) quick.