May 21, 2010 - 10:34 AM
For the days that you're going to be in Lauterbrunnen/Interlaken/Gimmelwald are you planning on traveling much? I'm sure a moderator will chime in as well, but I'm not sure it's a good value to pay for that many days if you're probably staying put for so many of them or just making small side trips. Unless the pass is very cheap, you may be better off getting a pass that only covers the days on which you are traveling a good distance and just paying point-to-point fares for the short trips on the other days. This is particularly true if your plans include some of the smaller mountain railways and cable cars (as well as the schilthornbahn and jungfraujoch excursion) are not covered by the pass. If you are taking lots of little trips you may find that a $99 second class half fare card is a good value for the intermediate days - this card entitles you to 50% off all second class fares.
It sounds like you have one long travel day in, one more from Lucern to Interlaken and environs, then back to Zurich. A second class ticket from Lucerne to Lauterbrunnen is only CHF37 so depending on the price of the pass that may not be a good-value pass day. You might consider the "Swiss Card" which is a bit of a hybrid - it includes your long round trip to/from Zurich, then gives you 50% off everything else, good for 30 days. A second class Swiss Card is $169 for those aged 16+.
You may just have to compare the different options to decide which is "best" for you. If you are staying put much of the time, the passes may not be as good of a value, but they do offer the convenience of just being able to "hop on" once they're validated. You can check fares on any route at www.sbb.ch (the website is available in english by clicking the little "en" near the top of the page).
Another thing to consider - when I was (ahem) a bit younger the youth passes were quite a bit cheaper than the adult. The value equation may therefore be different for the "kids" than it is for you. I'm not sure what passes cost these days.