I finally got a chance to use this in my last session and it was worth it! I skimmed through and picked out a dozen items that seemed fun to populate a very sketchy back room in a shop with. Be careful though, if your players are like mine they might try to take everything-- mine adopted a poison-eating purple cat and bought a Hellraiser cube. I'm looking forward to creating a hell-dungeon for them to run through on Halloween. I gave the box a couple of high DC checks before they can open it, just so they don't unlock it too soon.
This is a fun supplement. It has a lot of quirky ideas and they're organized well enough that you can fill a shop with them with no effort at all. My players were excited and loved everything, though be prepared to answer a lot of impromptu questions; it's probably a good idea to pick out your items a little ahead of time in case they interrogate you. The simple explanations in this supplement offer a lot of room for innovation and provide a good starting point for the imagination though, so still very well worth it.
[5 of 5 Stars!]