I recently had an oportunity to join a guild, after short talk with it's founder i purchased counterfeit membership instead giving him coins.
Since i have no intent to crate my own guild I'm a happy owner of something what's worth 400 coins without possibility of giving it to a leader or someone else.
Thing is: that ability of buying that licence should be disabled without guild houseOr maybe you should consider iteams from star menu as an objects which are tradable.