Lost Ark Gold is a currency that you will need all the time, which will allow you to buy just about anything you want from the Auction House, namely equipment, skins, engravings, potions, etc... but Gold will also be important to improve your high-level equipment. It is also used to exchange between players, buy Blue Crystals and it is essential to improve the quality of your items. Your progress in the game is determined by how much gold you have, so try to save it as much as possible and invest it in your main character.