Where: The basement of the university in Dementlieu, the room with said machine
When: Enchanted a pair of steel plated gargoyle hide gloves
What: When putting the gloves into the machine, it stated it would take 5000 exp to enchant them. After the process succeeded it took away 16000 exp, more than double the mentioned amount.
Screenshot:
https://imgur.com/j10v7ypRecreate: Try enchanting the same thing with another character, or perhaps any item if it's the machine in general
Ideas: Either it states the incorrect amount of exp it would take, or it takes more due to a bug I would assume. As for the cause I'm not sure if it's consistent with the machine, or simply due to the specific item in question.