Do you have items in your backpack that you no longer want? You can exchange them for coins so that you can purchase new gear!
To exchange items in your backpack for coins, visit one of the merchants in the town.
Merchants will give you coins for any items you sell back to them. Select the option to shop with the merchant to see what's available in your backpack to sell.
The coin amounts displayed under each item in your backpack indicate how much this merchant will give you for the item.
When you've found the item you want to sell, click on it, and then choose the Sell button.