Some really good stuff can be gotten simply by trading with teammates and the NPC's rather than tirelessly plugging away at dungeons and such. Listed below is what everyone has up for trade. Armor & Weapons are linked to their respective pages so you can have an easy look to see if you'd want them or not. Some names have been whited out to prevent end/post-game spoilers.
Party Members
Mia
Speed Charm
Beast's Bane
Knight's Bane
The Lovers
The Moon
The Hanged Man
Sealore