In a nutshell, one of the main purposes of FFXIV Gil Sales (abbr desyn) is to obtain the new i95 crafted primal/mog weapons, which are meldable, and probably HQ-able (HQ stats are better than what you see on the marketboard). If you already have Animus weapon, or even better, a fully melded Novus weapon, you may not care about it at all, and you may skip the rest of this discussion.
In summary, desynthesis is something you can learn at lvl 30 as a crafter. It breaks down a gear (NOT a mat! E.g. NOT iron ingot, NOT rose gold nugget) or a weapon/tool into some of its original mats. Each person can have only 300 points to be shared among all crafting classes, so theoretically you may have 3 classes at 100 points (max), but in reality, only 2 (due to the mechanics of how points are gained or lost).
Now, let’s work backwards. Each of the new i95 weapon recipes requires x3 “Demimateria of the Inferno”, 3x “Demimateria of the Vortex” or 3x Demimog Demimateria”. To obtain these demimateria, one must use desyn on the OLD primal/mog weapons. However, since those old weap are UNTRADABLE, you cannot hand it to another person to desyn for you. You have to DIY (Do It Yourself)! Yet, even for an experienced crafter, we can only have 2 classes specialized for desyn.
Therefore making it extremely difficult to acquire the demimateria. Furthermore, even if you successfully desyn a primal/mog weapon, we still dunno if it’s chance that u would get the demimateria, and I don’t know how many demimateria you can obtain from 1 desyn. However, once successfully obtained, the Buy FFXI Gil demimateria is tradable.
Same goes for the new i95 crafted weapons. Not only are they tradable, they are also meldable, thus a fully melded i95 weapon will be close to the powers of an i100 weapon.
This harsh requirement of OWNING an untradeable primal/mog weapon, and having the ability to desyn it properly obviously is S-E newest attempt to COMBINE DUNGEON WITH CRAFTING. Hardcore crafters are forced to run primal trials to obtain those weapons, and hardcore raiders are forced to level crafting to desyn their looted weapons. This is why instead of putting this “Desyn thread” into the Crafting & Gathering Section.