I think that something as fancy as a gown that was reserved for special times might not have the wear and tear that a regular everyday gown would have and that it would look good still. Remember that they did not wash their fancy fabrics. The main area that would show wear would be right down the front where one might spill drink or food and maybe the hem. So it does seem reasonble to me. They also did not have the availability to fine fabrics the way we do.