Getting back to the sale prices, if you find the sales somewhat distressing because you think they mean the series hasn't been selling well, phantom train, you might find it enheartening to learn that when I asked a BB employee today how long the sale would last, she told me until tomorrow, after which they'll go back up - and not only that, but they have new sticker prices on them that are higher than they were before the sale - one volume was priced at $99.99, another at over $100 (!), though I don't recall the exact amount for that one.
Presumably this means we can find joy in knowing the discs aren't selling so abysmally they need to fire-sale them. At the same time, I think anyone living near a Best Buy who wants these DVDs and hasn't gotten them yet would be well-advised to go get them today or tomorrow.