Given a travel related situation, and given a specific question about the situation, summarize the question into a title

Let me give you an example: The green carriage is of course first class. This would be our first preference with our 5 month old baby in lap, because of the presumably larger toilets for changing and whatnot. However, the baby being a Western white baby... will occasionally babble, screech or cry uncontrollably for a little while.

Speaking in terms of Japanese culture, should we avoid Green class tickets if we are taking aboard a potentially disruptive baby?

The answer to this example can be: Japanese train etiquette: Is it acceptable to take a baby in the Shinkansen Green Car?
Here is why: A person gives a detailed description about a situation where they would prefer to travel on the Shinkansen Green Car but is doubtful if doing that would be against the Japanese train etiquette since they will be traveling with a baby. The question is summarized as Japanese train etiquette: Is it acceptable to take a baby in the Shinkansen Green Car? for easy indexing the next time someone searches for a similar phrase

OK. solve this:
I am going to the Netherlands and might need to get a train. (Between Eindhoven and Amsterdam). On www.ns.nl (the large train operator that does that route), they list the price as 17.90ish. That's for booking it online.

However, I'm not sure what price it'd be if I were to turn up on the day and buy a ticket for the next train going that way.

Here in Ireland if you book train tickets online in advance, it's much cheaper than if you arrive in the train station and want to buy a ticket for the next train. (e.g. 20 online vs. 60 last minute in some cases). Is this the same in the Netherlands with NS or is it the same price regardless of when you book?

Update I don't care what sort of train to take, I just want to get from Eindhoven to Amsterdam.

Money isn't too much of an issue, I just don't want to be asked to pay 50 per ticket when I could have got it for <20 had I only booked online!

Answer:
Is it cheaper to book Dutch train tickets online in advance compared to paying on the day?