Carte Avantage? Worthwhile?

The value of the Carte Advantage depends on what the cost of regular train tickets are for the trips you will be taking on your vacation.
The Carte covers SNCF trains in France and includes local trains, intercity trains and the fast TGV trains along with Inoui trains.
The cost of the Carte is €49 per passenger. While the Carte does give a 30 percent discount off the price of a train ticket, you begin to benefit from it only after buying €150 of train tickets as then you have recovered the cost of the Carte. SNCF, the national train company, already offers heavily discounted second-class tickets for TGV trains when they first go on sale four months in advance of the travel date. For example, a Paris to Nice ticket normally costs €130 if bought on the day of travel, But if you plan ahead and go to the SNCF website when the tickets are first put up for sale roughly 120 days before your train trip, you can buy it for €20 . That is 85% less than if you bought the ticket on the day of travel at the train station. And it includes the mandatory seat reservation which can cost €20-€30! The walk-up fare for a Paris to Bordeaux TGV ticket is €120. If bought four months in advance when they are first released you can buy one for €25. And with the TGV train network covering so many regions in France including cities popular with visitors such as Paris, Lyon, Strasbourg, Bordeaux, Reims, Nice. Dijon Lourdes, Avignon, Montpellier, Carcassonne and St. Pierre des Corps in the Loire Valley— buying TGV tickets will get you to most regions in France and to get to the other locations on your itinerary may only require a half-dozen local train tickets. In more rural areas, local buses might offer faster connections than trains altogether.
You can figure out approximately how much train tickets cost for your itinerary during October by going to a website such as www.Omio.com or www.TheTrainline.com. For your December itinerary, there likely will still be many good deals on TGV tickets. You can get an idea from those websites what’s available. Then you can decide if the Carte Advantage is for you. The best prices can be found on the French national train company’s website www.sncf-connect.com
Have fun in France!

Thanks, Kenko, for the thorough explanation. I greatly appreciate that.

You’re very welcome.

Not sure this will work for you but SNCF had a Black Friday sale last year where the carte was half off, a great deal. You might try and monitor this.

Also I never got my carte, but I got a purchase confirmation email with a carte number. That is what I used to buy my tickets, in my case I used a human at a train station ticket office but I assume I could have just input my number. Make sure you print out whatever you are sent and have it with you as backup. I had a surly train conductor who insisted on seeing my actual carte.

First, there was a sale for several weeks last month--25€--but is over now.

Second, there are no more physical cards. It's what SNCF calls "dématérialisée" these days and is put into your app and their records. So when the "contrôleur" conductor, in English zaps your ticket on your phone, all the info pops up in his/her machine. My husband refuses to input his card number, so he always has to carry his receipt with him when we take the train. It resembles a supermarket receipt. The people at the train station have offered to input his info but he sticks to his receipt.