they're not rare, De Beers manually controls the market price by limiting the amount of diamonds on the market.

[u/valsagan]

[u/Present_Character241]

but now even nobles will not be able to and entire serfdoms will be thrown into starker inequality.

[u/TheArmoredKitten → u/[deleted]]

This is still assuming clerics or high wizards capable of resurrecting people ever gave a shit about the nobles problems. The material cost is still nothing compared to getting a functionally immortal arch-mage off his ass to help someone that isn't immediately of value to him.