For the benefit of my Solo RPG with no GM that relies on The Players honesty would you say that 180 Gold Coins each or 400 Gold Coins per set or 5,500 Gold Coins for the collection of all 13 sets is a fair price for the 13/1 each, sets of 1 large high quality silver neck-chain and 1 large high quality silver pendant is a reasonable sale value for the things that you identify The Assassins in Assassins of Allansia with?
I'm finding it difficult to give useful suggestions since it seems like you are literally making everything up as you go along. Only you know your created world the best I'm afraid. If using genuine FF rules, I'd say you've priced your pendants ridiculously high, even for their unique design. They appear to have no use other than to identify a person as an assassin. The silver chain would probably cost about 5 gold, and together with the pendant, around a total of 50 gold each at best, and mostly that is because I don't think Lord Azzur is a cheapskate. 180 gold for one though, even Lord Azzur won't fall for that.