Unfortunately, Aerogal (Avianca) does not fly from Cuenca any longer, at least this is what some sources have said. We found Aerogal to be the least expensive as well as have some really good deals if you buy advance tickets. We are disappointed about this. The video also has important information if buying your tickets online you might want to know.
Although we live in Cuenca, we visit Quito whenever we get a chance!