I'm based in Germany, and the Deutsche Bahn website is great for scheduling international train travel. It knows all about the train times and connections all over Europe. However, it rarely shows fares for trips which cross a border. All the other national train operators' websites I've tried have the same problem. This makes them rather useless for comparing prices when I've got a destination in mind and am trying to choose between, say, taking the train, flying, or renting a car... or alternately if I've got a budget but no particular destination in mind, and would like to see what places I can afford to visit.
Is there any website which will let me plan train journeys in Europe, and give me the exact or even approximate fares? (That is, something similar to the many flight search websites like Kayak.)