The only way to really find out is to list and price all your trips,remember you added advantages with the Swiss Travel Pass, like free museum entrance. if you use the Swiss Rail Website to cost the trip remember that it defaults to half price fares.
I have used the pass in previous years and I like it, I have often changed my plans when I've been on a train,also remember that you can loose out on the mountain railways, the main one is the trip to Jungfraujoch, where you only get a 25% reduction on the fares from Wengen/Grindelwald and back. Travel to there is included.
If you so decide to buy the pass buy it for the full time of your trip, which if I am correct would mean buying a 14 day pass.
You may well however find that the one month Half Fare Pass costing 120CHF is better value because then you get what it says, Half price travel on all transport even Jungfraujoch, BUT you do not the additional free or half price entrance to museums.