Travel Pass for 10 day trip?

Yes, the question is which one. A Half Fare Card (HFC) is a no-brainer, but you might also benefit from a Berner Oberland Regional Pass for your time in Muerren. As has been discussed here many times, you have to do the math, which is tedious. Plot out each leg of your journey and any lifts you expect to take. Be sure to check www.sbb.ch/en for fares. The site assumes you have a HFC so you need to double the price shown or use the drop down to see full price.

I have done an analysis many times and the Swiss Travel Pass and the Flex Pass have never made sense for us because we use the mountain lifts, especially in the Berner Oberland, a great deal. But the HFC plus the BO Reg Pass have always worked well for us when we have a stay in the Lauterbrunnen Valley.

"Berber Oberland" - I suspect an attack of the spell-checkers. The Berbers live in North Africa.
The website for the Berner Oberland Pass is here: https://www.regionalpass-berneroberland.ch/en/

The Swiss Travel Pass and Flex Pass come in, for your purposes 8-day and 15-day varieties. The Flex Pass is probably not worth considering, because for 8 days in a month it is only 40 CHF more than a 15-day Travel Pass. The 8-day Travel Pass would not be valid for your first and last days, which would be OK if you don't have any major travel on your arrival and departure days.

Another advantage of the Travel Pass is free museum admissions (for the most part) and free urban transport. A new feature this year is that it will include the Schilthornbahn all the way to the top at Piz Gloria. And finally, except for mountain lifts where you still have to buy discounted tickets, it is truly hop-on hop-off. So there is a convenience factor to consider.

But if saving money is the goal, the Half Fare Card almost always saves the most money. You still have to buy tickets for each journey, but it is always 50% discount. No museum admissions, but urban transport is also 50% off.

Finally, you don't mention the ages of your family. With either the Travel pass or the HFC, you can get a free Family Card and your kids 15 and under travel with you free.

My opinion, the Berner Oberland Pass is a bit of overkill. But as Laurel said, you got to do the math. You are going to spend a good chunk of change no matter what.

Hahaha Chris! Yes, the spell checker got me. Corrected now.

I'm interested in this Berber Oberland rail pass. Tell me more!

This is really helpful - thank you. The 8 day pass might be best since we aren't traveling the first or last days. My daughter is 13 - I didn't realize that the family pass is free!

It is available in Morocco.

I support your leaning toward the Swiss Travel Pass for 8 consecutive days. I used one last week and found it a joy, although (full disclosure) I was not the one paying for it. It fully covers some mountain routes but not others. Remember that you choose your travel-start date at the time that you buy it.

Other advantages for the Swiss Travel Pass is that castles are considered museums. So, since the Swiss Travel Pass fully covers (most) museums, it also covers Chillon Castle (on Lake Geneva) and Thun Castle (in the town of Thun by Lake Thun).
In the Luzern area, it also covers the transportation on Mt. Rigi, fully. It covers half the cost of the transportation for Mt. Pilatus and Mt. Titlis.
And it fully covers all lake ships/ferries (including the areas where you're going, Lake Geneva, Lake Thun, Lake Brienz, Lake Lucerne, and in Zürich).