$3, The Little Black Book of Dirty Jokes ($9 on Amazon)
$5, What to Do When There's Too Much To Do ($11 on Amazon)
$5, Kiss That Frog!: 12 Great Ways to Turn Negatives into Positives in Your Life and Work ($16 on Amazon)
$10, Super Freakonomics (Hardcover, $24 on Amazon)
$5, Why Zebras Don't Get Ulcers ($14 on Amazon)

Discount if buying more than one book; contact if interested!