I'm able to lutefisk all of brax's item and get out with no consequences. Just go into the shop and pick up all the items and lutefisk them. After that, just jump / teleport / potion out of shop. Alternatively, I just pick up the last item then put it back, Brax will just get back to initial place.
You can also use the museum thingy skill (experience for artifacts) on his items and you can just walk out ^^.
