Bookselling for School?

I was a little bit wondered about my travelbook: The author says thats its helpful to buy some copied books frm the chidren on the streets, because they need the money for their school fees. I was confused because I thought there is not really a fee (which is), but also if the booksellers even go to school (what they do not).

On the streetfriends-website I just found this paragraph:

The cost of a public education (registration fees, uniforms, supplies, mandatory private lessons) prevents many families from sending their children to school. These children then spend extraordinary amounts of time unsupervised, either loitering or earning an income. An accurate census of the homeless or street population has yet to be carried out. Depending on the definition and according to the figures accepted by UNICEF, there are between 600 to 1,000 street children who have completely cut ties with their families and have made the streets their home and 10,000 street children who have kept ties with their family and return home either regularly or irregularly.