I DID buy it in hardcover (mostly because I am a ho for anything Lackey, and own a good portion of the ones that were released in hardcover in hardcover, though I normally wouldn't buy Valdemar books in hardcover unless on remainder...I just saw this one at B&N and got excited).

And yeah, that fourth one is probably the Gryphon series (it's like a super-super-super-prequel to the Valdemar books). I've read pretty much all of them, and recognize their fanficness, but that doesn't stop me eating them up with a spoon. :(