Good way to earn Gil

I have this thing where I have to have one of every item, even if it is inferior to the items I currently have which is costing me alot of gil.
Right now I am at Mt-Bur-Omisace on my way to the Draklor Laboratory and I calculated and I need 40500 gil for the weapons and 29000 for the armor and then once I reach Dalmasca I will need 4200 for the technicks, 23300 for the magics, 24500 for the weopons and 35300 for the armor. And I'll bet that after that I will need more gil for more stuff.
I am tired of spending hours stealing and poaching, so I was wondering if anyone knew a good way to earn some gil. Alo, I refuse to sell old weapons and equipment.
I have mostly been going to the Ozmone Plaines and stealing and poaching those Mesmenir things.

I wish monsters still carried gil (at leats a decent amount anyways. You stole 40 gil yay) How do they pay for their late night monster poker games? I miss Final Fantasy IX where I alsways had tons extra gil. Why can't I transfer funds from one FF to the next? That would be awesome.

As a side question, what level should I be at? I am currently at Level 28, and the boss fights were easy, but in the Stillshrine of Miriam, I had to do alot of healing. I went into the feywood and I got my ass handed to me.

Thanks for the help

I used to know tons of ways to get gill, alas I haven't played the game in ages. I'll get back to you when I remember.

EDIT: You should probably wait till you get later in the game to get all the gear. The later areas give out gil from the stuff you kill much easier so it's less of a time waster. By give out gill I mean from loots and gear you can sell. If you have more than 1 of an armor from enemies I recommend selling it. I'm not saying don't get all the buy-able items in the game, just saying to put it off till you've saved up a fair amount... because for that point in the game that is a LOT of gil. Hell I'm far into the post game and only have 200k gil. (not including everything that I've bought/saving up for)

EDIT-EDIT: The Feywood is for later exploration. It is not for your level. Lv.28 if I remember correctly is fine for the dungeon you're heading to if you aren't stupid. You go through the Feywood to reach one of the longest dungeons in the game later in the story so don't worry about it yet. BOLDED TEXT

You just need to build long chains, the Sandsea is a perfect place to make a 100+ chain where you can easily rack up 99 of a ton of items to sell for loot. Basically just find areas with a mass quantity of the same enemies and just trudge from one side of the map to the next.

Another thing to do is just do all the Mark Hunts and be sure to talk to Montblanc when you kill optional bosses like the Earth Tyrant and Mom Bomb, as he often gives monetary rewards for doing this.

I completely forgot about the chain system. Made money making easy for me in my post-game play through. Also the sandsea is good, an alternative for quick insta-kill lp farming and money is the undead on the bridge in bhujerba mines. There will be a bridge with only hordes of undead. You should flee 2 maps whenever the mobs run out then go back. going 2 maps away re-spawns every enemy. I made it up to like 120-ish chain as soon as I got there last time I played and was funded for a very long time.
Not as good as the sandsea for money but fantastic for lp.

If you're in medium levels Sandsea is the most useful I've had.

Then if you're really need for the money in the part of the game, Ozmone Plains, chain those Wus just ignore everything else. Only Wus.

Feywood comes next as the Mirror Knights or whatever the walking owls they were. Dropped the Mirror stuff. Those are pretty damn useful. And when you learn to walk around correctly, chaining isn't going to be a problem, meaning you get 99 of everything they drop fast. Whenever you need the money, those are what I'd chain.