Secret Vault

Conjuration (Summoning)
Level: Arcane 5; Components: V, S, F; Casting Time: 10 minutes; Range: See text; Target: One chest and up to 1 cu. ft. of goods/caster level; Duration: 60 days or until discharged; Saving Throw: None; Spell Resistance: No
You hide a briefcase, backpack, dufflebag, or similar item in an extradimensional space for up to 60 days and can retrieve it at will. The item used as a secret vault can contain up to 1 cubic foot of material per caster level (regardless of the item's actual size). If you put anything living inside the secret vault, the spell fails. Once you cast the spell, the item and its contents disappear. You can retrieve it anytime thereafter by concentrating (an attack or move action), and it appears next to you.
To create the secret vault, you cast the spell while touching both the full-size container and a miniscule replica of it. The container and anything within it or touching it (subject to the volume limitation above) vanishes into an extradimensional space. You need the miniature replica to recall the container. After 60 days, the container reappears in your hand whether you wish it to or not.
Focus: A briefcase, duffle bag, or similar container prepared with expensive and rare reagents, as well as a miniscule replica of it. The actual storage container and the miniature replica have a combined purchase DC of 25.