Well given that the USD to CHF is pretty close to even, that is not a big deal, but lets use CHF.
The trip to Rigi Kulm and back is 144 CHF if you go by boat to Weggis or Vitznau, and 116 CHF if you go by train via Arth-Goldau. Or you could go one way and back the other for 130 CHF. But if you have a Swiss Travel Pass (STP) it is free.
Similar for Pilatus Kulm, different ways to get there with different costs, but it is not free with the STP. The STP will get you to the base of the lift free, then half price for the lift.
Same for Titlis. STP gets you to Engelberg for free.
However, for what you want to do, why not get a 30-day Half Fare Card for 120 CHF. Then you can use it to get to Luzern (you don't say how you are getting there) and for the train to Italy for the portion to the Italian border. Then everything, boats, trains, lifts, city buses will be half price. That will save you more money than a 4-day STP.
https://www.sbb.ch/en/leisure-holidays/travel-in-switzerland/international-guests/swiss-halffare-card.html