76 Residuum for a 14 key. 675 for a 385 piece

[Stabalicious-draenor (Stabalicious)]

@Legionkiller-moon-guard

It is earned through your weekly cache, on M+ completion, and from salvaging Azerite pieces you’ve obtained post 8.1.

This was on the blue post the other day. Not sure if they’ve changed it since then. But I can confirm they at least stated it publicly.