Almost everything sells for 1 gill on the market..

[KumaAkuma]

I don't really understand how you are supposed to make gill on a new server if basically everything you can obtain sells for 1 sells in the markets

And why are people putting it up for 1 gill at all

[Fiosha_Maureiba]

Depending on what Disciples you are leveling I think for gil generation (just raw gil generation into the economy):

Gatherers with Battle Classes: Treasure Map
Gatherers introduce treasure maps every 18-24 hours that ideally should be done by eight players. Even more ideal if the gatherers themselves have battle classes.
If eight gatherers each bring a peisteskin map, each map nets 1.6k to 5k gil per player. If 8 players each have a map, that's about 12k to 40k gil per player per day.

Battle Classes: Daily Roulette
Although not as delicious, if you player roulette into a level 50 dungeon and go through clearing most of the mobs and opening the Allagan coin pieces, you can come out with 2.5k to 4k a dungeon run after repair fees are factored. In Wanderer's Palace, two to three of these chests may be skipped regularly, causing the party to lose out on 600 gil each player from enemies and several Allagan pieces each time.

Crafters
With higher level crafters, there comes high level repeatable leves. An armorer can create high quality cobalt ingots into Mor Dhana Saints' Hold for about 27k gil a day. A culinarian with HQ apple juice in Limsa Lominsa for 36k and there are some others such as a leatherworker with HQ Raptor Leather or carpenter with HQ Mahogany Lumber.

Why Put it Up for 1 Gil?
I think it's a combination of retainer convenience and the idea of passing the item forward. e.g. if someone is going through their retainer and they just want to make space as quickly as possible, they can't just discard the item out right. They have to move the item into their inventory first, then discard it and/or remember to sell it in a bit. But if they just right click and put the whole stack up for a ridiculous low price of 1 gil or bare minimum vend amount, they can store new, more valuable stuff into their inventory and the materials may go toward a good cause in someone else's hands.

They may also reason that if they ever need to procure that item later, they only have to pay 1 gil or so for it with minimal listing and tax fees. This is pure conjecture on what others think as this is just what I think, in terms of getting 40 items off my retainers and into the hands of other players without caring about profit or making the items disappear from circulation.

[Zourin]

If you want to make items dissappear from circulation and help the economy, Discard is everyone's best friend, as anything going for less than shard value is a waste of time for the seller.

Just destroy trash, or vendorize it if you really want that 1 gil. You don't pay taxes on vendors, and may get 3 gil for the hq trash.

[Peptaru]

If I am given the choice to throw something out, NPC it for one, or give it to someone who will be able to make use of it for the same price... I'm giving it to the person who can use it for dirt cheap. Aside from recently added housing, there is nothing in this game that people need gil for. If my selling stuff really cheap helps someone become a self-sufficient crafter (sp), I call it a win, not a loss.