FINAL FANTASY XII THE ZODIAC AGE

So to spend 1,000,000 gil you've first got to have 1,000,000 gil. You'll get a large part of this from just normal play-through of the game, but for those who may be struggling or are just looking for a way to get a lot of gil for weapons, armour, magicks, etc a good way to make gil mid/later game is farming Mirrorknights in Feywood .

They drop an item called the Windslicer Pinion which sells for 1,148 gil each. They also drop Mirror Mail armour which sells for around 4,000 gil.

Mirrorknights are not the toughest of enemies and can be chained fairly easily.
Note the Feywood can be accessed fairly early game, but this is a level 40 area, so be warned if you try to come here at a lower level.

Best way i find to farm is in Walk of Dancing Shadow area in Feywood. The bottom right section is filled with just Mirror Knights. Start off in Antiquity's End (where the save crystal is) and basically 'loop around' the bottom of the map and take the closest exit (fleeing - RT) to Walk of Stolen Truths, back into Antiquity's End (dont use the save crystal or your chain will reset), heal/buff as needed, back into Walk of Dancing Shadow where the MirrorKnights will have respawned, rinse and repeat.

Watch out for the rare enemy Dreadguard! Again, not too hard, but would be dangerous for lowered leveled characters.

The usual Berserk, Haste, Bravery trick works well here. They're weak versus earth if you have a good Earth weapon. As the name implies, they have reflect on basically all the time so magick's out of the question.

I just did a run and got ‭153,652‬ gil in about 20/25 mins. My characters were level 36.

Also note this is a pretty good way to power level as well. With Embroidered Tippets you're looking around 1,800 exp/kill. Good for leveling if you're under, say, level 50.

One last gil related thing to mention is the Hunt Mark Behemoth King. Once you complete the hunt (and get that joke of a reward). Go to Mt. Bur-Omisace and to Temple's approach area. You'll notice halfway up there's a stone wyrm head. Remove Vaan's weapon and you'll be able to strike the head and you'll get 500,000 gil.
However this is much later game you'll need to be at least level 70 to take on Behemoth King and even then (IIRC) he's a tough SOB.

Hope this helps!