I had an idea that i think suits the server. It is called
Command XP Bank. What it does is that it can store your experience levels when you die. Before I say anything else, youre probably saying, ''well, we already have a plugin that does that, which is Death Control. so let me say that this is different (yes, this obviously wont store items) because
1. u can deposit xp levels whenever you want for a small price, and withdraw them for free.
2. u can share xp levels with other players, and
3. if u die for good (when u cant afford to be saved by death control) all xp levels in ur bank will stay there untill u take them out.
Link to official page:
http://www.curse.com/bukkit-plugins/minecraft/benatat12s-xp-bank