I don't think there is a small market place. In fact there is a big market place if you think Ella spawned at least 5 bios. A selection of the diary translated dealing with Queen Victoria & her family, The Hesse family, The Battenberg family would create huge interest. In fact if you look at the businesses of Paul Gilbert & Arturo Beeche came mostly from their printing of books and articles on the Romanov family.