Poor people, lol. Making gil is easy, it takes longer to do everything other than the alexandrite than to make 600m to buy 30k alex at 20k each, which is over paying by Odins standards.

http://wiki.bluegartr.com/bg/Light_Arts
This says lights arts increases skill levels to B, gives fast cast and reduces MP cost of spells. You can do more than that if you skill up your magic skills, you can cap cast/recast times with gear, and MP isn't an issue, so.......... what am I missing exactly? nothing? k.