DonAngelicoThat's just the lowest price point from a collection of ebay prices. If you look at the average ebay price, it's still hovering in the $100 range. If someone is trying to sell you the entire anthology for under $15, they're either a fool or they're trying to screw you over later.
DonAngelicoThey are including people selling off the individual sealed decks piecemeal. If you scroll down it shows you the EV of each paper deck and it looks like the lowest is $40 at this point. I'm betting that will drop as more of these hit the market, but the set will be worth more that $13 for the planechase cards alone.
DonAngelicoIf you actually look at the page you're linking, $12.94 is the price for ONE of the four decks included in this set, and doesn't include any of the planes or the dice.