Personally I think it is just the amount of NIB pins coming into the market. Something has to give when there is limited space and cash involved. This year alone these pins started shipping:

TnA, AC/DC Vault, Star Wars, GotG, Aerosmith, Dialed In, POTC (not shipping but people selling to prepare), Houdini (same), Alien (kind of), AFMr, probably some smaller runs I am missing. Then you add in that you can still get Ghostbusters, Metallica, Walking Dead, GoT, Hobbit, WoZ, Batman 66, all still on the line at one point or another.

It used to be that maybe three (sometimes four if it was the quadrennial JJP release or Spooky had a new pin) titles a year. Way more supply of the new shiny, demand hasn't taken up the slack, so prices on secondary market are going to take a hit.

Not stating anything new/revolutionary here, but what is more interesting to me is how/if this will impact the primary market. For me, if I take larger hits on the secondary market it means less money I have to spend buying NIB pins. More and more people are just going to say "f-it, I'll buy it for cheaper 6 months to a year down the road", which is smart, but without us (suckers) buying NIB, the availability of machines for the secondary market starts shrinking.

I think many of the manufacturers out there are only surviving because of the NIB collector market and the sky high prices of NIB machines, if that starts changing I think there will be shake out. Instead of 6? manufacturers could be down to 2 or 3 (or even 1 or 2) left standing.