Just looking for some thoughts on a situation I currently have in my group...
I've explained Elite advancements to my group, but I've always had the rule that if a skill or talent appears somewhere in a character's progression path, then they must wait until they reach that level to purchase the advancement. This was mainly to stop things like over-zealous second rank Guardsmen purchasing Heavy Weapon Training (Plasma) or something similar.
One of the players plays a Sister Dialogous at the fifth rank of progression. The group has spent a lot of time tracking down a Daemonhost in the service of a rogue Inquisitor, and has even once ended up in a conflict with the creature. The Sister Dialogous character has done significant research in to Daemons during this time, and now her player has asked me if she can purchase Forbidden Lore (Daemonology) as an elite advance now, even though it appears in the eighth rank of the Adepta Sororitas path.
Personally I feel that the reasoning behind the purchase is sound, but now I'm trying to work out the best way to handle it. I've considered either just taking the cost of the advance at rank eight and adding a few hundred points to the cost, and/or requiring the character to take some more insanity/corruption points while taking the skill to imply that the character learned knowledge that her mind was not yet prepared to comprehend.