It wasn't just the matter of raising the price of my bones, but to limit the number they'd get from me.
For example, a single diamond grade bone would give me what tens of thousands of blue grade or green grade bones would.
The simple logic would drive me to keep the high grade ones to myself and exchange the low grade bones with others. But when I thought about the grander picture, this wasn't a great thing, not good.
Giving one high grade bone out in return for saving tens of thousands or even more of the lower grade ones would be better.
Like this the enemy would only get one bone to grant power to others, affecting only a small and limited number of their forces. Yes these few would gain scary power, and for a much longer time, but their extremely low number could be matched by my universe's elites and strong powers.