I've been offered a Diana 100 side lever 10 Mtr rifle which to me, from a few pictures and a verbal description, looks to be about 8 out of 10 condition but it has no rear diopter sight. I have no pictures to show and I haven't seen the gun in person yet but I could use some help with a 'Ball Park' price guide as these Diana's seem to be quite rare and don't come up for sale too often so I have nothing to base an offer on. I would like to add this gun to my collection of 10 Mtr rifles so any price help appreciated. Thanks.