Well, you have to be careful what you buy. There is also a Saver Day Pass, which does not require the Swiss Half Fare Card. The cost starts from CHF 52. A Saver Day Pass is refundable provided you buy a full fare ticket instead; it is not refundable when buying a Supersaver ticket. You can check with the SBB Contact Center if they exchange your Saver Day Pass into a full fare Saver Day Pass: +41 848 44 66 88.
The cost of the Swiss Half Fare Card is CHF 120 and well worth if you are taking multiple trips and doing mountain excursions. As a rule of thumb, it pays off if you spend a total amount of CHF 240 on public transportation tickets.