Inspiration won`t study because of low black bile.

[Kandarim]

i'd say it's pretty straightforward: you lose one point of black bile for each profiency point you get. Keep in mind that the server multiplies displayed values by 1000 (e.g. a fresh alt is 5000/5000/5000/5000 to the server). Proficiency points that wasted over your cap are not brought into account. I'm unsure what happens with proficiency points that became re-available because the cap goes up due to invariance, but it wouldn't be hard to test.