Both F3 Many Gates of the Gann and F1 The Fane of Poisoned Prophecies are included as part of the After Gen Con Sale put on by Pacesetter Games & Simulations. Right now both modules are $9 each (the lowest price I've seen either of them), there are lots of other cool modules available, and there's free shipping with $50 in purchases:
http://pacesettergames.blog.com/2012/09/07/convention-news/
But Bill only has a limited supply of F1 and F3, so if they've run out, you'll have to get them from other sources at a slightly higher price. (Click on the product pages to the right for the other sources.)