Enter code 'APRILFOOLS' at checkout. This will give you 10% off for a savings of up to $25.
While I mention that for my own book, I would also point out how many other authors have some great product out there. You can pick up a hardcover version of Swords and Wizardry, a one-book edition of Swords and Wizardry White Box, the latest copy of Fight On! or Knockspell, X-plorers, or a pile of other goodies.