Talking about switched prices: I read recently about Amazon and Squaretrade. Apparently, Amazon pulls in the Squaretrade warranty price dynamically when it renders the page for an item; and Squaretrade uses some sophisticated model to determine the price. So if you add it to your cart when you're buying the item, you are not guaranteed to get the same price you saw; the price of the warranty in the cart can often be much higher.