If this weren't the Pope's Hall, and if it hadn't been for the deterrence from several Titled Douluos present, it's likely that someone would have already been unable to restrain the greed in their heart and rushed forward to snatch these treasures.
Initially, when Tang San used the King Yama's Invitation to kill his enemy and obtain a soul bone, it was also a skull. Therefore, when he saw these three soul bones in front of him for the first time, even his steadfast will couldn't help but waver for a moment.
This was a soul bone! To a Soul Master, this was the most precious of treasures, something that one could only happen upon but not seek.
In soul bones, there is also a hierarchy of quality. The inherent quality is extremely important. The higher the level of the soul beast that produced the soul bone, the greater its efficacy. Of course, this does not include attached soul bones.