You can already book your tickets for Culinaria. Last year, they did not sell out and you could still get them at the door, but word has spread from 2011 to this year, so you never know… You will find all the details on their official website and can also read more in this recent post and last year’s review.
The weekend menus are bigger than last year (7 courses instead of 4) and of course, prices have gone up considerably (EUR 75 advance sale, 5 euros more at the door) but more or less proportionally. Unfortunately, it looks like Thalys won’t be offering any discounts to its Thalys The Card holders this year.
You can still go for a 4-course meal, but only if you go for lunch on Thursday or Friday. Lunch will set you back EUR 55 on site or EUR 50 if you buy your ticket in advance.