Unique

Today in class we talked about a certain unique object being less rare or less unique as time goes on. I don't think that this is something that I agree with, while the initial appeal of its uniqueness may be gone but for instance if it were a "one of a kind" item then it would be unique for entirety, it would be unique to the owner and to all who see. The only difference is how comfortable we become with an object during a particular time which can change how we view the uniqueness of an object. Do you think that a work of art that is once viewed as not "unique" can suddenly become it?