DFI is correctly valued, I am sorry to say...It is a well know fact in the industry that DFI resources had some zone higher then the feasibility and some zone lower. Furthermore, it is also a well know fact that DFI exploration work was not complete, it lacked some detail...
Yes it was good enough to mine to rich stuff, but the weakness and lack of control over the deposit is now coming back to bite them, as they have to mine lower grade horizon....
The reason why they are only getting these low price is simple, IMO, the tool just cannot go to bed rock, therefore they are only mining the smaller size diamonds found on the surface....before the real pay dirt...this will teach them to buy an hold piece of Crap of Gemfarm....