Trading Block

My idea is that we basically have a block you can craft in survival, that basically you can use to sell items to other players even when you aren't online. The idea was that you basically have a 3x3 grid to put the items you will be selling in and then be able to look up the item you are looking for in return. But eventually when all your items have been bought, the block will reset to an empty one. Also you will be able to receive the items you wanted in return, in a square in the corner.