I'm with pwalker and lorddun. I'm sick of the publishers manipulating the ebook trade so we can't get what we want at a reasonable price (or can't get it at all). I'm sick of them exploiting the author.
His books are at a reasonable price, the author gets the money, and the books are DRM-free. I grabbed both books on offer, plus most of his short fiction. Good value, and the publishers and big retailers don't get a cent.
Interestingly, "Once a Hero", one of the offered $5 ebooks and not a recent title, is currently available in paperback from Borders AU at $50.95 (USD $42.65).