Items with enchantments might have hidden markings that could be used to indicate their ownership. If you were careless with an unfamiliar item with such a mark, you could get into serious trouble when you come into contact with powerful people.
Normally, these markings wouldn't be a problem if you knew where they come from and who they could get you into trouble with. But that changed when you were dealing with something that belonged to a corpse or items that a beast had accumulated.
The former owner of such an enchanted item might have been the child of someone powerful. If Vicente took it with him, he could possibly arouse the suspicion of people he didn't even know about his involvement in the death of such a person.
Since he didn't know anything about the basilisk's victims, he put those items aside, even though he thought they were valuable and could help him.
