I will be going from Amsterdam to Rotterdam this summer, by train, as it seemed the most feasible. Precisely, 20 July. I am not living in Netherlands, so buying the ticket from the office right now is not an option. If I buy the ticket online, the ticket sending and reservation fee cost too much. My question is, would it be possible for me to buy a ticket two days before the departure time in Netherlands, from the office? Or do those trains run out of tickets really fast?

Thank you for your attention