Percy Jackson & The Olympians Books 1-4

Set of four books in the Percy Jackson and the Olympians series by Rick Riordan, including The Lightning Thief, The Sea of Monsters, The Titan's Curse and The Battle of the Labyrinth. My kid bought the books used, except #3 was gifted to her new. After reading multiple times is finally ready to part with them. Price is firm and will fund her next book purchase. Thanks.