Bloomsbury Academic Press is running a 30% off sale this week, ending Sunday, May 12. So you can buy ¿Por qué? 101 Questions about Spanish for $25.86 (plus tax) instead of the usual $36.95 ($35.68 on Amazon). Delivery within the US is an additional $3.50.
(The first link above will take you to the Bloomsbury purchase page; the second will take you to the book info page on this blog.)
Stock up now — this book will make a great birthday or holiday present for your favorite Spanish teacher(s)!