Answer:
In The House on Mango Street, Esperanza is hanging out with her neighborhood friend Cathy who offended Esperanza by suggesting that the neighborhood was getting bad because people like Esperanza and her family were moving in.
Whilst they were together, a girl named Rachel walked up to them and offers to be Esperanza's friend if Esperanza would give her five dollars for her and her sister to buy a second-hand bicycle.
Esperanza agrees over Cathy's objections because she figured that getting 2 new friends and partial ownership of a bicycle for $5 was a good deal.