Kate Middleton's sparkling engagement ring, which originally belonged to the late Princess Diana, sports a giant sapphire surrounded by 14 diamonds... and now it can be yours, too, for just $19.90! Americans have taken a shine to the ring, just as they have to the betrothed British royal couple. Knock-off versions abound, ranging from the precious and pricey to cheap and cheerful, and are a temptation for all those who dream of being a princess, too.