Glamour.

But serious answer: there's the raids, naturally, as well as Extreme/Unreal content. There's also one of my personal favorites: treasure maps. The L80 maps typically go for about 50K on Mateus, so the L70 maps should be a bit cheaper, yet you can make some major coin off of them. If you're particularly flush with gil, you could also try out housing as well (though I would suggest starting with an apartment, as they are cheaper and more readily available than housing plots).