HELP! Train advice for Switzerland and France

You got a seat assignment automatically when you bought the TGV train ticket. It should be on the ticket along with the number of the car where the seats are.
Did you get an e-ticket or are you having them mailed to you?

Do not buy the Swiss Travel or Swiss Half Fare pass in advance. There is no advantage to doing that. You can easily buy that when you get to Switzerland at the train station.
Same thing with the mountain excursion, you would only buy that on the day of when the weather is clear.

Don't rely on a guide book if you want know the exact fare.
You can look these up on The official Swiss Rail website
https://www.sbb.ch/en/home.html

Don't use RailEurope. They are a reseller in North America that doesn't list all trains and can cost more. Buy direct from the company running the trains.
For Basel to Paris, that is TV Lyria: https://www.tgv-lyria.com/en-CH
Or use the SBB website: https://www.sbb.ch/en/

Seat reservations on TGV's are not a separate process, the tickets include them automatically. On your tickets it will state date, time, train ID, coach and seat numbers.

Both those sites allow you to select a number of passengers. On the SBB website, Basel to Paris on 30th May is currently CHF 171 per person for the first train (08:34), same for the 10:34 and CHF 91 for the 12:34, and CHF 74 for the 14:34 (I didn't check later trains). Looks like the very cheap tickets are already gone, you must have bought the last one!

For train times and costs, use the SBB website. The "from" price assumes you have a Swiss Half Price Card. Click on purchase to find the full fare. Swiss tickets are valid on any train on the date shown on the ticket, seat reservations are of course NOT needed (or even possible) in Switzerland.

Routes up Schilthorn: It is the cable car, or a mountain hike. Or, if you are a Bond Villian, a helicopter.
Actually last year some tourists got a free helicopter ride down: https://www.thelocal.ch/20180622/stranded-tourists-airlifted-from-iconic-schilthorn-peak

Any more questions, feel free to ask.

I ran into a similar problem with a TGV trip Geneva to Paris. I ended up booking the trip in two separate transactions to get the lower fare. The tickets did automatically have seat assignments. My daughter ended up in a different car (20 years old)She could have moved since there was plenty of room on the train, but enjoyed her peace! I did that once with Airline tickets when I discovered that the per person fare for 6 people was much greater for one person.

I have not found RS train fare map to be particularly accurate or helpful. I use loco2 and trainline to get an estimate of a saver rate by playing with dates a bit. For Switzerland we ended up buying a Swiss Travel Pass. We broke about even on it and it was a convenience. Then we could just walk up to the counter and buy day of tickets. You have to do the math. I never use RailEurope. Their prices are higher than the individual countries' train sites and more than loco2 or trainline.

In general, I wouldn't by the Swiss passes in advance. I did because the prices were going up prior to my trip. I'm also told that some times they run specials. Can't imagine that would happen for summer.

Thanks to all of you. Have never used RailEurope before...and won't do it again!! I have always used loco2...it is so much easier!! Have already bought the tickets and printed them so I guess I am glad to know that we at least got them somewhat cheaper.. My husband did it so I did not see the seat assignments. That's one less thing to worry about!

Good thoughts on the Swiss Pass. Since we really only have 2 long trips(Basel to L'brunnen and return) I think we will just do point to point tickets. Should I go ahead and get those now? AND NOT USE RAILEUROPE! That way if the weather doesn't cooperate we will not have spent the money for the Schilthorn trip.

Thoughts on lake cruises out of Interlaken???

Thank you all!! Very helpful...I am feeling better!

Swiss train prices are always the same, with one exception. They have Supersaver tickets which go on sale within 30 days of the day for as much as 50% off. You must travel on the exact trains shown on the tickets. Normal full fare tickets can be used on any train that day on that route.
https://www.sbb.ch/en/travelcards-and-tickets/tickets-for-switzerland/supersaver-tickets.html

If you have a lot of travel on a given day, you can also get a Saver Day Pass. They start sale 30 days before the date of validity, and prices go up as time passes, so you should buy as soon as they go on sale for your travel date.
https://www.sbb.ch/en/travelcards-and-tickets/tickets-for-switzerland/1-day-travelpass/saver-day-pass.html

Or see whether a Half Fare Card would be useful -- for us it came out about even to buy HFC for trips Lausanne> Mürren> Lausanne plus Schilthorn plus trip Mürren> Lauterbrennen.

(Basel to L'brunnen and return) I think we will just do point to point tickets. Should I go ahead and get those now?

No, just buy at the station on the day, from the ticket machine or the manned ticket counter (on the left as you enter the station). There is no discount for advance purchase on (most) Swiss trains. A standard ticket, whether bought on the day or in advance, is valid on any train that day and costs CHF 68.60 full fare, or CHF 34.30 with a Half Fare Card.