So I've an idea, GMs should make Diamonds drops on EVERY Mining spots, with a percentage like 1~20%.
Tailor VS other jobs materials - Tailor materials can be select but others cant, so once Tailor GM, you just have to look for what you need, but other jobs are not, like Blacksmith, once Diamond Spots runs out, YOU'RE GONE! or Bowmaker/ Carpenter, whitebirch are rare like Diamond.

GMs please consider it!