well really how many times have you went into a dungeon or some other tower or even boss kinda place well why not increase the amount of getting the item or items bye floors each floor would be 5% increase (maybe).
example 1: trying to get life sword from redwing (cant remember the first part of name)
example 2: golem paladin his life deck almost impossible to get if your life or any other shcool
example 3: life school only amulet =that gives druid this is a VERY rare amulet and lots of people would pay big money for it because its so hard to get
note: i am a life wizard trying to get all of the above.
the reason its so low is because it has to balance with the drop rate of all the other potential drops it has farm till you got decent drops whatever you dont want you seel and what you want you keep simple then go to the bazaar and see if you can get a life sword