Lisbon doesn’t have many must-see attractions, but the whole place is charming and is an excellent travel bargain compared to similar cities in Europe. Hotels and hostels are unusually affordable considering the high standards here, and bargains are usually easy to find outside of the busiest summer months.
Most of the attractions are free or cheap, and don’t forget about the famous Tram 28 that trundles through all of the interesting tourist neighborhoods in one loop as you get to ride along with locals for a normal tram fare.
Food and drinks are also quite cheap by European standards, with particularly good local dishes and wine available at modest prices. You’ll pay more to eat at one of the restaurants featuring fado music, but it’s a premium worth paying at least once.