I would advise taking the bus. Portugal has great bus service. Once you get to Santiago, there is a direct bus from there to Lisbon. Lisbon is worth a few days. Once there, you can take the metro to the main bus stop at the zoo station stop. There is regular and reasonably priced bus service to Albufeira. I made the mistake of driving from Lisbon to the Algarve a few years ago and the road tolls alone were almost 50 euro.
Hi there! We did the Camino from September thru October and then went to Albufeira. We had to take a flight from Santiago de Compostela airport to Seville and then a bus will take you right to Albufeira.
Hope this helps! Buen Camino!!