You can also take the train from Lisbon to Lagos from Gare Oriente. Price is € 4.00 to € 6.00 more than the buses.
The Advantages are that you can wander around, not be cramped and if it is a nice day you get to see a lot of the rural Alentejo. There is also a cafe/bar onboard. Its also worh it just for the privilege of crossing the 25 Abril bridge over the Tagus where you have a great view.
Was up in Lisbon at the weekend and came back on the 13:20 Sunday train from Gare Oriente. It was great and the countryside was beatiful. Lots of happy free range porkers running about under the cork trees. :))
Bear in mind the last 1 hour to Lagos is by local train from Tunes Junction.
