I've seen this volcanic vault item.. and it's the size of a quarter. It's going to be packed into something.. Just like those adventure packs that have the character, the zone item, and the two extra pieces... the volcanic vault is the same size as those small extra items.. yeah I might be...
Some of the items are timed exclusives, I'm sure that volcanic vault will be release in a 3-pack just like
The Darklight Crypt... which is a Toys R us exclusive... but can be pre-ordered from Wal-mart right now. http://www.walmart.com/ip/Skylanders-Adventure-Pack-Darklight-Crypt-UNIV-Wii/17350849
Some of those Exclusive characters and items are only "Timed Exclusives".. You will be able to get the other characters at other stores probably within a month or two when they release the other figures...
i.e.
Skylanders Spyro's Adventure Pack - Darklight Crypt is only a Toys R Us Exclusive...