Sellers can now make offers to buyers who have carted their items. In the Me Alerts (they moved  from the Alerts and are now in Me Alerts) you will see an alert when someone has carted your item. Tapping on this alert will bring you to the offer screen where you will be able to send an offer/set a shipping price. This is a way to bundle/offset any shipping charges for buyers who want to purchase multiple items but a seller doesn't want to have the buyer pay extra shipping.