Originally Posted by
JoostvD
Thalys does not have frequent sales.
Sorry, but you are wrong. If you sign up for the Thalys email list, you will get regular offers for the sales. Happens all the time. As the OP is going from France to Brussels, he would sign up for the French emails to see the sales. Or if he goes ex-Brussels, sign up for that list.
I hope you realise that Thalys is a 'premium' service. You can travel cheaper if you use local express trains instead of Thalys.
Not really. There is no local Paris-Brussels express train. And if you do CDG-BRU, it is almost always more expensive than the Thalys.
Sometimes at the last minute (or just a few days before travel), if you have the time and really need to save every dime, you can get a cheap fare going Paris to Lille, then pick up the Eurostar from there to Brussels. But if you get the Thalys on one of these sales, it is definitely cheaper.