Gil and Monsters dropping it

[Estellios]

Do leves at high difficulty and do the evaluation every 9th leve to get the gil bonus. I believe the bonus is higher if you do leves from different cities. Probably the best gil you can do without dabbling in the game economy.

FYI, as was stated the reason gil doesn't drop from everywhere is because online games have an economy that offline games don't have to deal with. Having gil drop everywhere would drastically reduce the value of it and you'd need even more to get anything done.