traveling in Switzerland Berner Oberland

You can search fares on the official rail site
https://www.sbb.ch/en/buying/pages/fahrplan/fahrplan.xhtml

Note that the first fares shown on the SBB site assume that you have a Half-Fare Card (since almost everyone in Switzerland has one). If you don't have one, the fare is double. For the trip you're asking about, the fare is CHF 5.60 (each way) with the card, or CHF 11.20 without.

You may think that sounds like a lot for just a 20-minute trip. You'd be right.

You can find the exact prices at a glance on the price list here:

https://www.jungfrau.ch/en-gb/prices-and-brochures/

Yes, they are expensive, BUT I look at it in terms of TIME, not distance.
How long would it take me to hike uphill from Lauterbrunnen to Grutschalp? About 2 hours and sweat. The cost to get up there is about $10. Is my time worth $5 an hour? No!

I'm going to guess that the original poster has not been up there. My advice is to go there, and pay to see if it is worth it. I'd say 99% of the people who do (on a clear day) say it was well worth it.

And if you think that's expensive, don't even look at Mürren-to-Schilthorn(!) --but well worth it on a clear day.

And all of the above journeys are covered 100% by the Swiss Travel Pass

Lauterbrunnen to Murren via Grutschalp is about 15 bucks total, one-way. However, Switzerland uses smackers, not bucks, so it might be closer to 13 smackers. If you're British it's about 10 clams. If we all used simoleans this would be much simpler.

If you consider the engineering and quality that go into that cablecar ( which you will appreciate when you ride it), it is not all that expensive.