I found websites about all the night trains that travel between major cities, but I can't seem to figure out what I would actually have to pay as a supplement/reservation in addition to my Eurail Global Pass. Is it worth it, instead of paying for a hotel....just to travel on these at night. Would it be possible to buy them the day of? I know my basics, but not exacly which day we're doing what, so I wouldn't be able to make the reservations far in advance.
I like night trains because they save the cost of a night in a hotel and allow extra daylight hours for sightseeing. The cost of a supplement/reservation on night trains depends upon what kind of accommodation you wish (from a reclining seat to a private sleeper). Click on the railpasses tab at the top of this page and do the same on www.seat61.com to learn more. Night trains on popular routes often sell out. It's best to make reservatons for those as far in advance as possible.
You can find the cost of reservation (accommodation supplements) or of full or discounted complete tickets for most night train that have one end of the route in Germany, as well as book these fares, on the Nachtzug Reise website, www.buchung.nachtzugreise.de. Click the British flag for English. These are the fares charged by the night train lines themselves, the same thing you would pay at a counter in Europe.
City Night Line, which is one of the lines on Nachtzug Reise runs trains from all over Germany to Zurich via Basel. They also have their own website at www.citynightline.ch.
You chances of getting on a specific train with your choice of accommodations at the last minute are almost zero. I have seen night trains booked up a month in advance. Also, the best fares, SparNight, which usually cost less than reservations plus a day of your pass, will sell out by the day of travel.
Also, Euraide.com has fares for night trains all over Europe.
One small but important correction to Lee's post. Use "www" if you want to view the main night train site (www.nachzugreise.de). However, if you wish to go directly to the booking page, leave off the "www" or you'll get a "page not found" message. Just enter "buchung.nachtzugrgreise.de".
Lee, I may indeed be correct, but I also made a typo. I inserted a couple of extra letters. It should be "buchung.nachtzugreise.de".