I have an idea to add a feature for selling items where, when a user wants to list an item on the Marketplace, there will be a button to "Sell for a fixed price" or "Set your own price". The "fixed price" would be that minimum price for which the item is currently sold on the Marketplace, which I believe is already shown in the inventory when you click on the item to sell it – it's written at the bottom.

In my opinion, this would be super convenient. When someone wants to get rid of unwanted items ("junk") in their inventory, they would just click the "Sell for fixed price" button. If they want to sell it for a higher price, they would click "Set your own price". This would speed up the selling process because currently, to sell an item, you have to manually type in the price, which takes quite a bit of time.