This station is very good.
There were even guides directing foreigners to the right ticket office - students of English maybe.
However, do not believe any station ticket seller that announces no tickets left.
This is because they want the passenger to go to the agents and pay more, which results in the station ticket seller receiving kickbacks from the agents.
If they insist, and the police do not react, go to the next station up the line and buy the ticket you want there. That station does not have an arrangement with the agents.
Apart from this danger, the station is a great place to wait for a train, and you will pay Thai prices for refreshments.