Please don't misunderstand what I'm about to say.
I did not build this website to justify my collection to anybody. Do I realize, as collections go, that it's one of the smaller ones? Of course! This site was built with a purpose in mind (answered below), the least of which was trying to impress anybody.
When communicating with other collectors of magical props, etc., one often hears "I'll show you my collection if you show me yours." Previously, at least for me, that meant sending out several photos via e-mail, messenger, etc. Now, it's simply a matter of sending a link to my URL.
That means that I have more than one of that particular effect. Unless there is a truly significant difference in the two or three, etc., I prefer to state "duplicate" than creating another listing. On the other hand, if there is something which makes one standout as different, i.e., there are several variations of the Sucker Die Box, then it will receive it's own listing.