Where should I go to farm Gil quickly in Final Fantasy 13?

I'm trying to complete the last achievement that I need in FF13, the one where I need to upgrade all the weapons/items to hold every item possible in the game. I'm wondering where I should take my fully maxed out party to farm gil that yields the best possible gil per hour ratio.

Solution 1:

From the official Strategy Guide ...

Leveling Spot # 3: Eden - Leviathan Plaza

Spot Details: The Adamantoise offers some of the best rewards in the entire game: 40,000 CP, a Platinum Ingot as its normal drop (sell price 150,000 Gil), and a Trapezohedron as its rare drop. The latter component has a resale price of only 10,000 Gil, but is essential to create "ultimate" weapons and costs a massive 2,000,000 to buy.

......

In addition to "premium" components that are designed purely to be sold, there are several standard components with a Gil value that far eclipses EXP or multiplier increases that may offer during weapon or accesory upgrades. Acquiring these can be a great way to generate funds for purchases.

Name               Sale Price (Gil)
Gloomstalk         1,000
Sunpetal           1,000
Moonblossom Seed   6,000
Starblossom Seed   13,000
Succulent Fruit    1,750
Malodorous Fruit   4,000
Green Needle       3,500
Perfume            12,500

Solution 2:

I used the stradegy outlined in this video to farm the Leviathan Plaza Adamatoise.

After I had gotten used to the battle and had a fully upgraded Crystarium I was able to finish each battle in around 1:42. For battles that did not yield a drop I would quickly exit to the title screen and re-load my game instead of bothering with the extra time to save.