My husband and I are going to Paris for 5 days and then we were going to get an unlimited rail pass so we could hop on and off at our leisure for the next 8 days. Then someone said you need additional tickets for any of the high speed trains. So we are trying to figure out the best way to travel. After Paris we were planning on time in Germany,maybe Czech, Austria and finally Switzerland where we will catch our return flight. Suggestions?
Some of the trains in Europe are considered "premium" trains, the cost of which is not completely covered by a railpass. For these trains you must pay extra, over and above the railpass. The additional fee is call a supplement, but because these trains have mandatory seat reservations, paying the supplement gets you a seat reservation. For that reason, the supplement is sometimes mistakenly referred to as a "reservation fee". Thalys trains (Netherlands, Belgium, France, Köln) have a fairly substantial reservation fee. Italian Eurostar charges about $15 per train. Not sure about TGV. In Germany, almost no trains except the high speed ICE Sprinter have a reservation fee. I've made 8 two-weeks in Germany since 2000. For the first trip I bought a railpass and realized after that I just barely broke even. Next seven trips I analyzed the cost of a rail pass vs. p2p, didn't buy a rail pass, and saved money. A lot of money can be saved, particularly in Germany, with advance purchase tickets. So, "hop on and off at our leisure" is a very expensive luxury.
You can only hop on and off trains that do not require a seat reservation. Generally those are the locals or regional trains -- different names in different countries. And you do not want to be on a train that requires a reservation because the fine is expensive. The old days of hop on and off trains is almost over.
As the others noted, usually the only trains you can "hop on, hop off" with a rail pass are slower regional trains (IR)... which tend to be rather cheap anyway. Because you want to visit several countries (that's probably too much for 8 days, by the way), you probably will use mostly intercity trains (IC or ICE). And as the others have pointed out, with a rail pass, you need a supplement for these. What will most likely be far cheaper is to buy your long distance 2nd class train tickets in advanced. You'll usually save a significant amount of money this way. For any short day trips, just buy the tickets when you arrive to the station. And finally, don't use Rail Europe, Eurail or any other third party ticket reseller to find schedules and prices. Used the individual national rail company websites for each country (Deutsche Bahn for Germany, SNCF for France, ÖBB for Austria, and SBB for Switzerland.... off the top of my head, I can't remember what Czech rail calls itself). Rail Europe and the like mark up the prices and don't show you all the options available.