I have been checking the various retail outlets, and the price change to make Tribes and No Safe Haven $2.99 again is in place in the Kindle, Nook, iBooks, Smashwords, and Sony ebookstores. Kobo now has Tribes back (it had lost it for a while) but the book is still priced at 99¢, and there's no sign of the other two novels. Diesel has still lost all my books! And the newest outlet, Blio, has Tribes and The Sixth Discipline, both for 99¢ but with no sign of No Safe Haven.
Actually, Blio is no longer the newest outlet for me, because I recently uploaded The Sixth Discipline to Goodreads in ePub format. You can buy it there DRM-free, just like Smashwords.