Originally suggested this in the dungeon thread, but figured this deserves its own thread.
Basically a setting for shop stands that allows you to limit how much of an item can be bought per player account. (as opposed to per player character, since 1 player can have up to 10 characters)
This has 2 uses.
One is to give away free stuff without having 1 person take everything (or him logging onto his other characters to take it)
The second, more important purpose is to allow player made dungeons to properly reward players. The only way to give rewards in dungeons currently is to offer items for free (in which 1 person can take everything) or have a token or storage system, both of which requires meeting up with the player to trade.
This suggestion would therefore solve this and allow for more player creativity.