(Obtainable around lvl 30+) Magic Crystal73 (+3 Crit on Accessory) - I can't remember where exactly you get this but if you quest grind in Amarkand you will eventually stumble at this quest. this can sell for 1.2m+
(Obtainable around lvl 40+) Greater Crystal of Haste (+3 Movespeed) - You can get the quest at Algon's Post for this and this one sells for about 3-5m.. I see a bunch of people selling it at that price range
If someone has a more specific info or additional info please feel free to post it