Audible.com Win-Win sale (through Sept 18th) has more than 200 books for $4.95 each.
A number of the sale books have been reviewed by Bookwi.se
Jim Butcher’s Dresden Files books, Nick Carr’s The Shallows, Emma Donoghue’s The Room, Neil Gaiman and Terry Pratchett’s Good Omens, Superfreakonomics, Drive: The Surprising Truth About What Motivates Us by Daniel Pink, Live Free or Die, Falling Upward: A Spirituality for the Two Halves of Life by Richard Rohr, Agent to the Stars by John Scalzi, Snow Crash by Neal Stephenson, Mistakes Were Made (But Not By Me), Intelligence: A Novel of the CIA, and Solaris by Stanislaw Lem
And several other books that I have read but not reviewed here (Belgarath & Polgara by David Eddings, Contact by Carl Sagan, Once and Future King by TH White).
Also 1Q84 by Haruki Marakami has to be the greatest cost per dollar of the sale (nearly 47 hours for $4.95)