score:7
So, after coming back from the trip I thought I would update.
As well as ticket desks, there are also a long row of ticket machines at Alges station, to ensure tickets can be bought 24/7. Tickets can be purchased from those machines, and must be put through the barrier to gain access to the platform of the station. Different types of ticket are available, and you should keep them until after you disembark the train.