# BOOKS           TOTAL PRICE           % DISCOUNT                PRICE/BOOK

1                            $19                                    regular                             $19

2                            $30                                    ~20%                               $15

3                            $42                                    ~25%                               $14

4                            $53                                    ~30%                             $13.25

5                            $57                                    ~40%                             $11.40