Regular point-to-point tickets cost the same, regardless if bought in advance or at the counter. They are good to travel on any train.
Prices indicated by default are “From” prices. The lowest fare is usually a Supersaver ticket. Supersaver tickets are indicated by a % sign. These tickets are only valid for the selected connection. Further restrictions apply.
I suggest looking at the Saver Day Pass which might be cheaper than a regular full fare point-to-point. The price is increasing the closer the travel date and tickets are subject to availability.
Currently, Coop and Interdiscount stores do sell day passes for as little as CHF 49. They are good on any train and are also available without half fare card. This might be another option to save on travel costs.