When are you travelling exactly?
Sometimes you do good to check prices from Lille, it is usually a bit cheaper. It might be also an idea to check out the carte avantage of SNCF (this carte avantage can be bought quite regularly with 50% discount too).
Ordinary ticket + carte avantage will probably still be cheaper than a pass + reservations.
When are you travelling exactly?
Sometimes you do good to check prices from Lille, it is usually a bit cheaper. It might be also an idea to check out the carte avantage of SNCF (this carte avantage can be bought quite regularly with 50% discount too).
Ordinary ticket + carte avantage will probably still be cheaper than a pass + reservations.
It will be 25th of June, and back a week later on the 2nd of July!
I did Brussels to Chamonix earlier this year. The long way round (via Cologne, Basel) because of French strikes.
There are several other routes you can check. The direct TGV Brussels - Lyon, then TER to St Gervais and Chamonix. Or, as Brendan says, try from Lille.
You can also go via Paris, and take the TGV Lyria to Bellegarde, then TER to St Gervais and Chamonix. Or the same TGV all the way to Geneva, then a bus to Chamonix (which may works out quickest).
There are some other direct trains from Brussels and Paris to the Alps, but I think they only run during the ski season.
I’d agree that regular tickets would probably be cheaper than a pass, since you don’t have any other journeys.
For now I get weird results, probably because the TER timetable is not known yet in the Auvergne Rhône Alpes. Perhaps someone else might know when these will be available?
The prices are also different on NMBS/SNCB Europe than on SNCF connect. It also gives weird results, mainly on the SNCF planner (but that’s about the worst planner in existence, always leading you to expensive options 
)
Genève or Annemasse or Saint-Gervais-les Bains might be a better option as a destination, than Lyon for Chamonix. From where you can continue your journey with TER or the Mont-Blanc Express. The Mont Blanc Express might make the last part of your trip a bit expensive. But again, timetables seem to be incomplete for your preferred dates.
Prices from Lille are usually cheaper than from Brussels. You can get cheap to Lille by choosing the NMBS/SNCB trains. With a standard Multi to Mouscron, and then a short local ticket Lille-Mouscron. Shouldn’t set you back more than 15 EUR to get to Lille.
Although it might be wise to go to an international guichet/loket to pimp your ticket as a through journey (local train Brussels-Lille, then via TGV to either Lyon/Genève/Annemasse/Saint-Gervails-les-Bains Le Fayet, so that you don’t get in to trouble with rebooking in case of delays on one of your trains.
This is quite difficult to do yourself online, but I’m quite sure they can help you with that at the ticket office :)
