The titular Treasure Seekers are rewarded by a boon, surely, but it isn't the boon they were expecting. Instead of literal money, they find a happy, wealthy, gregarious uncle to help them. This is a picture of family, but in a more secondary, communal way. Alone, the family has too many children around the same age to really survive the downturned economy, but together with their relatives, they might have enough.
It is important to the family that their children be given private educations, but that is actually a detail of the book that might not make sense cross-culturally. In Indian culture, many people believe in castes, which are like social orders, which they believe are all sacred and play an important role in society, but they are ranked in a hierarchy. This idea might be offensive if it traveled to, say Sweden for instance.
But in its context, it helps make sense of the plot; the father is not just afraid of destitution. He is afraid that somehow he has failed in some way that has permanently lowered his family. He is scared of failure. When we meet the uncle, we see that he is not scared of failure. He is happy and loud and boisterous, and he has more than enough energy to keep the kids entertained; the true treasure is the uncle's demonstration of confidence and happiness.
