New Ring Item Slot

To add more uses to wondering traders I think for a decent amount of emeralds (or maybe rubies but that is another suggestion in and of itself) you could buy Ring Items that you can equip on your character. This could be in its own item slot. These rings would provide minor but noticeable gameplay impacts which is why I'm not too keen on the cost being just emeralds. Examples could be:

Glow Ring - Provides limited constant lighting whilst wearing
Ring of Regeneration - Provides increased natural regeneration whilst wearing
Ring of Strength - Increases your attack by X amount of damage whilst wearing
RIng of Speed - Increased movement speed whilst wearing

You could come up with some unique ones on top of this. I think it would make for an interesting gameplay addition that would add more flavour for your character, you could even get some unique rings from either milestones (one could be crafted from a nether star) or certain chests like Bastion or End Cities.