Trains

Half-fare card is the best deal for us.  I have it as 190CF below, but a 30 day half-fare card is available for 120CHF.  This makes 347.90CHF/person or with a 1.14 exchange rate, $1586.42 for the 4 of us.  I also changed my mind about going to jungfraujoch, so took those fares out, and we decided to go from Stechelberg up the cable car to Gimmelwald and then walk down hill to Trachsellauenen and back to Stechelberg, and then take the cable car from Stechelberg up to Birg and back down to Mürren to check out the views at Birg.

Passport quality photos are required for Half-fare card and can be on paper, or digital.  An identity check is required.  Mailing the passes takes 10 days.  Passes can be electronic.  I'm not clear about whether at a train station you can buy a half-fare card and use it immediately.  It really sounds like they will not take a picture of you and you must provide one.  

This is where to get tickets for the lift between Isenfluh and Sulwald:   https://www.isenfluh.ch/deutsch/preise/

Use WCs on the Train

To save time and money, use the toilets on the train rather than those in the station (which can cost money). Train toilets are located on the ends of cars as indicated by a WC sign (water closet).

I do not see any charges for luggage on trains.  If you can carry your own luggage, then you can put it on a rack like on the hotel shuttles at the airport.  There is no guarantee what no one will steal your luggage.  Keep your eye on it.

Return trip in Switzerland means the same as "round trip" does in the US.  Spread sheet image below assumes CHD 1 = USD 1.14:

From our assumptions in August: 

From our assumptions in May: 

Hotels: 

Hotel Stubbach, Lauterbrunnen

Hotel Interlaken, Interlaken

Hotel Alte Post, Grindelwald

Hotel Schonegg, Wengen

Hotel Eiger, Murren

Holiday Inn Express, Zurich Airport