Concept

Add a new item and recipe. Diamond Nuggets (name suggestions welcome).
                
                1 Diamond <-> 9 Diamond Nuggets

This would allow for selling things at the cost of a partial diamond, without having to worry about exchange rates to other entities.

Why would this be enjoyable?
It improves the market capabilities and would allow for more standardized prices (through diamonds)

How does this improve the server?
It would help with promoting a stable economy by having a primary form of currency (diamonds) 

Complexity to Implement
Probably a 3. It would require a new item and 2 new recipes. It would also require an adjustment to the Shopping Mods that allow for certain items to be recognized. I'm not certain of the complexity, but I don't imagine it to be that complicated.