The books are in very good condition!
Starters - Enders duology by Lissa Price

Book content:
After an unimaginable catastrophe, only very old and very young people remain. Without any means, 16-year-old Callie and her little brother fight for survival on the streets. Callie therefore decides to do the unthinkable: She rents out her body to an old person, whose consciousness takes over her body and can thus become young again. But everything turns out differently than planned ...§16-year-old Callie loses her parents when a sinister infection kills everyone who is not vaccinated quickly enough; only the very young and very old survive. While the elderly increase their wealth, the young fall into poverty. Hope is offered by the Body Bank, a mysterious institution where young people can rent out their bodies for money. The old person’s consciousness takes over the young body for a while in order to become young again. But things go wrong for Callie: She awakens before she is supposed to, in a life that is completely unknown to her. Instead of her wealthy tenant, she inhabits an expensive villa, has luxury in abundance and falls in love with the young Blake. Soon, however, she discovers that her body was rented for a secret purpose, to carry out a terrible plan that Callie must prevent at all costs ...