One other thing to note: All aetherial gear are modified versions of HQ crafted gear. So, an aetherial sphene ring would be an HQ sphene ring with some bonus stats. This is mostly important as it means that, like normal crafted gear, you can spiritbind it to make materia. Likewise, not all green items are dungeon drops. Plenty of them are crafted "vintage" items, which are crafted using "damaged" armor dropped in dungeons. Like other green gear, they have a higher item level than their equip level, so they're stronger than other items, but like crafted items they can be spiritbound. Likewise, there green crafted items that are over level 50 crafted using materials from high level gatherers and materials bought with tomestones.