You scoff with no argument while failing repeatedly to provide clarification that AdeneleneDawner is asking for. You haven't done what you said you were trying to do, show why you think an action falls beyond the fuzzy line, but you've insulted others for a perceived crossing of it.
Why not sell the guy the swords? You're taking it as obvious, but I don't think it's clear to others (it's certainly not clear to me) what your reasoning is. The guy is probably schizophrenic, and so can't be reasoned out of his delusions. He might be treatable with medication, but if he doesn't have a legal guardian, nobody can force him to receive treatment as long as he's staying on the right side of the law and isn't a danger to himself or others. Plus, schizophrenia frequently does not respond to treatment, and if he's able to take care of himself, full time treatment would probably do a great deal of harm to his quality of life, so the expected utility of having him institutionalized would probably be negative.
If you don't have an argument for why selling him the swords leads to less utility, perhaps this is a moral intuition that should be dispensed with.
Duping someone with clear mental disabilities into giving you their money is a canonical case of something that normal people regard as wrong. Regression to that canonical case, combined with the appeal to subjuctive reciprocity ("Golden Rule" here) was my argument. When someone's morality permits them this much, there's not much more I can offer, as any obvious common ground is clearly missing, and efforts to cover the gap not worth my time.
I would not want someone to so milk me out of my money if were schizophrenic, even and especially if the...
http://eternal-earthbound-pets.com/Home_Page.html
Providing assurance that pets will be provided for in the event of Rapture.
Having thought it over, I'm OK with the ethics of this service.