Luggage storage at train stations

Yes there are lockers at both.

Cost depends the size. I remember seeing one for 8 CHF

Follow-up question: If I buy a point-to-point ticket from Basel to Lauterbrunnen, via Bern, does this allow me to get off at Bern and spend a few hours there, before continuing to Lauterbrunnen?

Also, is there any advantage to purchasing my train tickets online before my arrival in Switzerland? I am traveling May 25 to 31, and I am not purchasing any of the Swiss rail passes because I anticipate my total rail costs to be under $200.

Thanks,
Nils

Follow-up question: If I buy a point-to-point ticket from Basel to Lauterbrunnen, via Bern, does this allow me to get off at Bern and spend a few hours there, before continuing to Lauterbrunnen?
Also, is there any advantage to purchasing my train tickets online before my arrival in Switzerland? I am traveling May 25 to 31, and I am not purchasing any of the Swiss rail passes because I anticipate my total rail costs to be under $200.

If you purchase a normal (not a "saver" fare) point-to-point ticket, whether ahead-of-time online, or on-the-day-of at the station, then you can get on and off, anywhere, any time that travel-day, as long as it's on the same route you purchased.

There's no price advantage for purchasing regular train tickets ahead of time--they're the same price as if you "show up and ride." (Only the "saver" fares are restricted to a specific train time.)

About train station storage lockers, I remember there are luggage lockers, in the Luzern station, by Platform 3, past Burger King and past the Tourismus (Tourist Office). I also think the train office upstairs will store your luggage for you, but that costs much more than the lockers.