I like the idea of, if you get all items of a similar item, like the elemental staves (or +1's), you could trade them in to an npc with some sort of quest to get a single staff, a rainbow staff maybe, which includes the elemental benefits of all the staves in one staff.

Same for other similar groups of items. You have had to gain the gear first anyway, so you have them all. You can get all the benefits from them, you just have to gear swap.

But having one item with all the benefits would save inventory.

I like it.