Should I work with it?

Well, they were earned and used before 4th job was even released. How is the game going to handle that?

Oh, and Doom is a 3rd job skill, so you'd use a 3rd job reset. They work on the skills, not the points. However... I'm guessing that also means they could only be added back into a 3rd job skill. So if he reset them from Doom, he couldn't then put them into Genesis or whatever. Does anyone know for certain?

So on that note, it probably wouldn't be worth buying them, unless you wanted to move points from Doom to Door or something. (Somebody remember this puzzle for the next Tespia, maybe?)