From Gamer Escape's FFXIV Wiki, the free Final Fantasy XIV encyclopedia
In addition to the below listed items, the Calamity Salvager allows for the repurchase of numerous previously obtained items that you may have discarded. As such, items available for purchase will vary depending on conditions met by the player.
Players from version 1.XX can speak to this NPC in order to retrieve any extra items that had to be moved as a result of decreasing inventory space for 2.0. They can also trade in Cracked Materia and gear with Cracked Materia to restore it. Unique armor and weapons that can only be obtained once from an Achievement or Quest can also be repurchased here, such as the Meteor Survivor Ring or blue weapons/tools obtained from lvl 50 class/job quests. Also sells the Major City unique rings that a character will start the game with, and you can also swap certain gender-specific gear for the opposite counterpart.