My wife and I will be on a 62 day trip through Switz.,Austria, Hungary and Czeck Rep begining on Aug. 15. My AVIS lease for the entire time is $4,200.00. Buying train tix on a per day basis will cost about $2,500.00 . The Swiss Pass according to Rick on page 400 is good only for 15 days. One of my concerns is taking side trips where trains don't go such as visitng the Swiss Jura and the chasseron from Murten . Your thoughts please.
You can always rent a car for short duration to go to places you can't get to on a train. I've done it several times.
In Switzerland, probably a 30-day Half Fare Card for 120 CHF is your best value. Swiss Travel Passes are overpriced for what most people use them for.
Did you include in that $4200 the cost of fuel, 5 to 6 USD per gallon, vignette stickers for Switzerland, Austria, Czech Repubilic, and Hungary. If the lease starts in one of these countries, it will probably include that country's vignette.
The Swiss Pass is available for 3, 4, 8 or 15 days at different prices.
Details on the SBB (Swiss Federal Railways) website here: https://www.sbb.ch/en/leisure-holidays/travel-in-switzerland/international-guests/swiss-travel-pass.html
Anywhere In Switzerland not on the rail network will have connecting bus services, though not up to the one-per-hour frequency of the rail network. Buses (and boats) are included in the Swiss Pass. You can look these up on the SBB main page here: https://www.sbb.ch/en
The nearest town to Le Chasseron is Ste-Croix, which does have a station, with the obligatory hourly service from Yverdon-les-Bains, where the mainline trains stop. You can see this on the Swiss rail map here: https://www.sbb.ch/content/dam/infrastruktur/trafimage/karten/karte-sts-pass-gueltigkeit.pdf
There are of course places in Switzerland that you can only get to by train (no roads)!
As Sam says, with a car you need to factor in the cost of fuel (which is currently at the ridiculously cheap price of CHF 1.60 per litre, see here: http://www.theaa.com/~/media/the-aa/pdf/motoring-advice/fuel-reports/january-2018-v-2.pdf ), and tolls
And don't forget parking.
Using a combination of trains and short periods of rental car has worked well for me for long trips. I haven't done it in Switzerland but did in France for a month long trip a couple of years ago. I used trains for some long distance connections plus a short (6 day) rental car for Provence and then again a longer (17 day) rental car for Normandy and Brittany. I could have leased a car (because it was over 21 days) but this worked better for my itinerary and budget. Some places just work better with a car but I wasn't keen on long drives between my bases and I certainly didn't want to deal with a car in the cities.
You really have to do your research and look at your itinerary to see what might work best.