<< waiting can only see fares exhausted or go up?>>

This is not universally true>

Is it generally true?

Again if sure why wait?

I can confirm from very recent experience that Trainline ( https://www.trainline.eu/ ) is more reliable for booking with an American credit card than is Voyages SNCF ( https://www.voyages-sncf.com/ ). Where SNCF rejected my CC for purchase of PREM TGV tickets, Trainline accepted my CC for same tickets. Both sites pull schedules and prices from the same database, and both offer e-tickets for maximum convenience.

Not everyone's experience is the same:

https://www.tripadvisor.com/ShowTopi...in_Travel.html

Just recently booked 3 trips with trainline.eu - easy peasy! Got good fares a little over 60 days out - was not able to book at the 92 day mark. One thing I learned - the good fares are more frequent not on weekends and at different times of day, the fares can vary greatly. Using SNCF was always a nerve racking experience for me!

One wonders why SNCF makes it so difficult to book easy peasy as trainline? They obviously have to pay commission to trainline or is it more lucrative to steer folks to SNCf's subsidiary RailEurope?

I don't find SNCF difficult to use at all. I use it to book train tickets all the time. The only difference, I think, is that I have a Carte Bleue and not an American credit card, and that's what SNCF wants. Why should it not? It's the French National Railway.

I don't think they pay a commission to Trainline, but I could be wrong. Anyway, now that Trainline is available to anyone with any credit card, apparently, what's the problem?