I don't know when this started since I have a Prime membership and frankly, I don't care. Apparently, some items are "add-on" items that are priced so low that it would be "cost-prohibitive" to ship by itself. Therefore, it has to be shipped with other items to exceed $25 or you can exceed it by just changing the quantity of the item itself to exceed $25. Proceeding to checkout is impossible, the item is removed from the cart. Changing the quantity at the final page, removes the add-on item. Basically, if you buy something labeled as an "add-on" item, be aware that it's going to cost you at least $25.