BEST WAY OF PAYING FOR TRANSPORT?

Hi cassie1, and welcome to this forum! Whether a Swiss rail pass is cheaper than buying regular tickets, depends on your exact travel plans. In your case, the difference between both options isn't that big (not even CHF 20,-, and that's without the costs of public transport in Zurich). If you'd opt for a rail pass, the Swiss Half Fare Card would be your best choice.

For example: if you want to make a day trip from Grindelwald to Mürren via the cheapest route (Zweilütschinen-Lauterbrunnen), you're better off buying regular tickets. But if you pick the scenic route (via Kleine Scheidegg and Wengen), a Swiss Half Fare Card is already cost effective. This goes for all more expensive alternatives/detours/extra trips you didn't mention in your list. So if you want to be able to adapt your plans and include last minute trips or scenic routes, I would advise to use the Swiss Half Fare Card.