When the Duchess of Cambridge gives birth to her firstborn in July she will no doubt be inundated with baby gifts from fans around the world.  And for those with deep pockets who want to splash out on the third in line to the throne, the luxury market is awash with products fit for a future king or queen. Topping the price chart is a $20,900 Cinderella carriage-shaped crib from poshtots.com, which Beyonce and Jay-Z reportedly snapped up for their daughter, Ivy Blue [...]