Quote Originally Posted by VerdeLuck View Post
Given the way housing works, these items would be sellable secondhand for people who had never cleared ultimate through sharing housing.
You can make the item only function like that if the original owner is also owner/tenant of the house. If that player isnt the owner of the house anymore, the weapon loses its effect with it. And you can then also make the regular version available through other means, making even the effectless weapon, worthless in value.

Alternatively, the item gets removed from the housing when the owner is no longer attached to the house. As its unstackable with anything, it wont be usable for other exploits in housing. (the item is moved to the calamity salvager)

Selling becomes meaningless this way and just a waste of effort and gil. The only downside is that people can use this to scam others by showing that item in the house... but at the same time... it at least punishes those people from doing those trades and sustaining a system that is flawed (and at least they still get a house).