High Numerologist's Adna Quillcross shop bug

[Disorder]

NPC Adna in temple of Nine Faced God has a relic for sale called Nine (looks like a burnt book). She sells it for 0 gp despite it's a relic that unlocks 4th circle spells, has no min lvl requirement and got 2 charges of see invis per day.
In my opinion it should cost at least something. Relic is of Knowledge domain, which is not a bad one.