We are used to take a rede-expressos.pt bus from either Lisbon 7 Rios or Oriente to Lagos. Single fare 19 Euros; direct trip 4 1/2 hours (direct to Albufeira, then all stops to Lagos). FWIW in your case.
Thank you Fraluchi!!! I think , if I did it correctly that I booked the train for a Promo of 9 Euros each!!!!
Another forum member glanced at my plea to help me validate that and appears I did it correctly, though some site had the cost at $80 Each....
It was difficult to decide bus vs train, but my girls voted train!
*** Edited to add, I don't know where I posted that question as now I don't see it, but meant for it to go under this RV sub thread...