Good Luck with that, the only way to get a housing permit, is to purchase it from the NPC for 450k. The only reason someone will purchase it is to construct their house, and once you construct your house there is no point in buying another one unless you decide to relinquish your land and buy another house (which is unlikely at the moment). And as far as I know, the construction permit is untradable, so they will have to give you gil.

Pretty much you are asking if anyone is willing to pay for your house, and unless you know someone who is really generous, this is highly unlikely.