Belgium to Switzerland by train
3. Re: Europe Train Travel (Belgium-Swiss-Italy-France).
Without going into a detailed itinerary (since I do not know your exact dates), I can say that if you want point-to-point tickets, the time to buy is NOW! (with emphasis!)
Your best options for Brussels to Interlaken would be:
06:25 Brussels Cologne Interlaken (changing once)
08:24 Brussels Cologne Basel Interlaken (changing twice)
10:24 same as above
10:25 Brussels Frankfurt Interlaken (changing once)
prices for mid April ranges from €140 to €400 (for your whole family)
" Current rate of 1050 Euro is making sense .."
Seriously? You are looking continuous pass for 15 days. What most people do not consider is that with 15 days continuous pass, any day that you are staying put, you will lost that money (i.e. losing €70 per day if you are not using the train)
If you are keen using the pass (and I am not suggesting that you should), a 6 day pass in 2 months would be more appropriate.
However, you are travelling in France, for which a Eurail pass is NEVER recommended, due to the restrictions and quotas for Eurail pass holders.
And I quote:
" However, making reservations for TGV trains before arrival in Europe is strongly recommended. There are limited numbers/quotas of reservations that are available to Eurail pass users, particularly at the most popular travel times.
You may be told when trying to pay for a supplement at a station that is not possible to only pay the reservation/supplement on a TGV and will be offered the cheapest ticket available - likely to be a full price (non-discounted) ticket!"
And since you are travelling in Italy too, Eurail pass is an overkill for travelling in that country, where cheap point-to-point tickets can cost as low as €9 !
In short, reconsider your Eurail pass mindset, consider (build a spreadsheet for your travels in Switzerland, and compare) buying a Swiss half fare card. Fix all your cross border travels, and buy point-to-point tickets for France, and Italy.