When you get those sizes in small samples on the distrubution curve the kimberlite pipe will have bigger and bigger stones in the that pipe and thus you have a very good start in making a mine as well $$ values are needed.Those 2 stones alone would command a very good price.
There is another company that found a 9.9 carat rough stone valued at 60,000 US dollars for a rough diamond.
Canadian Diamonds top the world in Price because of there High Quality