The most stand-out feature of the game is the economy system, which is based on the in-game currency called PED (Project Entropia Dollar), which is pegged to the real USD at a ratio of 10:1. This means that 10 PED equals 1 USD.
Every item which has a PED value can be instantly sold to the in-game Trade Terminals (often abbreviated TT). However, some items may be valued higher than their actual PED value by other players due to rarity or them being used as an ingredient when crafting a popular item. This is where the Auction comes in.
The three main pillars of the economy are hunting, mining, and crafting. Hunters and miners are gathering materials necessary for the crafters, while the crafters are the ones supplying the miners and hunters with weapons, tools, and gear. The Auction is the center of it all, and provides a place where the players can buy and sell their items and resources.
The Auction is, like the name suggests, an auction system, where the seller is specifying the start bid and the duration of the offer. It is also possible to set a "buyout", which is a higher price than the start bid. If the buyer accepts the buyout, the auction ends and the buyer will receive the item immediately, instead of waiting the duration (max 7 days) for the auction to end.
There are also physical shops, often located in the in-game malls, where the owner of the shop can sell items by putting them on shelves and in display cases. This "avoids" the auction fees and has no set duration. You can also meet and trade in person.
Loot
When you attack a creature, the ammunition you spend is worth PED, and every shot is a kind of microtransaction. The value of the ammunition is transferred to the looting system, where it is used to calculate your loot once you have killed the creature. The full formula is not known, and there are many different variables that can affect the loot. However, the main principle is that the loot is based on how much PED you spend killing the creature. You can receive less value than you spent, but you can also receive more than you spent. And if you are lucky, A LOT MORE!
The same principles also apply for both mining and crafting, where the result is based on the amount of PED spent.