Swiss travel pass or half fare with BernerOberlanf

Without doing a spreadsheet of math, my guess is BO + 1/2 fare card but to know for sure you'd have to make a list of each of the trips you hope to take and price them out on sbb.ch and compare. SBB defaults to half fare pricing, so account for that in your math. The differences between options probably won't be massive so if you don't have the time to over analyze, you most likely won't be making a mistake that's going to cost you massively.

Just wondering if you have specific reasons for staying in all of these three locations:
Wilderswil, Grindelwald, Mürren

Travel time from Wilderswil to Grindelwald is half an hour on the train, Mürren is a bit longer at 48 min. If you were to stay in just one of these three locations and travel around the area from there you would save a lot of time not having to check-in and out of hotels and you would do all of your traveling without luggage, come and go as you please, check the weather and go where it looks the best, etc.

Probably you have considered this and have reasons for staying in all three, just wanted to make sure you were aware of how close these locations are to one another.

I believe from personal experience that is the best combo for you is a Half Fare Card and a Berner Oberland Regional Pass for 10 days which should include your arrival and departure days. You will get a discount on the BORP for having an HFC.

You might also benefit from a William Tell Pass in Luzern. https://www.tellpass.ch/en

As you will be staying in so many different regions (as I do), you might get the most benefit from the Swiss Travel Pass. The BO Pass won’t help you outside of the BO.

I am looking at the exact same comparisons for the same basic time frame (14 days) and regions (Zurich-Montreux-Zermatt-Wengen-Lucerne-Zurich). I did prices for Swiss Travel Pass 15 days + Zermatt extras + BO extras vs 1/2 Fare Card/SBB Saver Fares + BO Pass + Zermatt extras. The difference came out to $30 or so. Even if my math is off by a bit, it's so close as to be a wash. If I add in the cost for the William Tell Pass for the Lucerne region to the BO Pass, the STP comes out ahead. I think we will end up buying Swiss Travel Pass with the Zermatt/BO cable cars/gondolas as 1/2 fare extras. Think it will give more flexibility if we change plans bc of weather or unforeseen events. You may have made a decision by now but thought I'd offer more structure to the excellent previous advice that the options are quite similar.

For us it came down to a question of how many lifts we want to ride in the Berner Oberland. The First, Eigergletscher, and Pfingstegg lifts at Grindelwald, the Männlichen cablecar, train to Kleine Scheidegg, and other means of mountain transport are fully covered with the B-O pass, versus 50% with a Swiss Pass. Neither will fully cover the Jungfraujoch train (which we will not do anyway).

Look at the validity map and you will see that it covers more than just what we think of as the Berner Oberland. In your case it will fully cover the train as far as Gstaad on your way to Montreux, and the rest is 50%. It also covers travel to Luzern, but a 10-day B-Onpass will not include your Luzern dates. Maybe consider the Tell pass for that.

https://www.berneseoberlandpass.ch/assets/Uploads/BLS-BO-Pass-M-23-WEB.pdf

I generally advise people to just get the Half Fare Card, and then a regional pass for the area they are in.

One advantage is that you can turn things upside down. In stead of figuring out how much the minimum amount of travel will cost you, you can stop worrying about it, and max out your travel. There is no law against going up the Männliche multiple times. Heck, I even go up there just to have lunch. The Berghaus has quite a good kitchen.

So get the pass, stop worrying about what it all cost, and just roam about as much as you like. That is the best way to explore this area. Allows you to change your plans at whim, and just go where the weather and your mood takes you each day.