I didn't even know F. Paul Wilson was on Smashwords until I read something about his newsletter. He has a free Repairman Jack story here:
http://www.smashwords.com/books/view/15264
And several novels for $2.99 or less -- including
The Keep and some of his medical thrillers:
http://www.smashwords.com/profile/view/FPaulWilson