The toy store was where the children experienced a culture shock into a rich side of town compared to the "slums" or poor side of town in which they come from.
Sugar: Their are different elements of the story that we see from Sugar. We first see that Sugar and her family suffer from poverty when she asks Miss Moore "can we steal?". We also see growth in her as a character maturity wise. She is the one who has the epiphany and learns the lesson that Miss Moore tries to teach the children. Sugar realizes that the money used to buy the sailboat could feed all of them for a year.
In contrast to Sugar is Mercedes. We can see that Mercedes is better off than the rest of the children. She told the others that she can't wait to go back to the toys store with her birthday money. This irritates the rest of the children.
The story shows that things were not fair between the black and white people in 1972. The white people were given more opportunities to make money and support their families. They were also able to buy expensive toys while black families struggled to put food on the table.
The mailbox was down the street from where they lived and is was where Sugar verbally said what the lesson was.
The taxi cab showed the lack of maturity. The children were messing around by making fart noises with their armpits and placing bets based off of the meter. It can also be seen as a portal to a higher society and out of poverty where they had a realization of the differences between economic classes.