Trashlands by R. L. Stine

Set in a dystopian future where plastic waste has become the world's most valuable currency, the story follows a resilient young woman named Coral who lives in a community built from discarded materials. As she navigates the harsh realities of survival, Coral dreams of a better life for her son, while grappling with the moral complexities of her world. Amidst the chaos, she encounters a mysterious stranger who offers a glimpse of hope and change, challenging her to confront her past and redefine her future in a land where everything is disposable.