What the heck is going on at Target?

It's weird enough that Target has apparently had a secret horde of Guardians of the Galaxy figures in their back room for the past few years, but look at those prices:

$19.99 for the new ones is fairly typical, but why are the old ones $4 more? And at the same time, some people have reported finding the new Spider-Man Legends (the ones that let you build Sandman) for $12.99. What is happening over there?!