There is no absolute answer to this question because the price of a Hello Kitty cake, or any party cake for that matter, would depend on a lot of factors. It would depend on the type of cake you have chosen, the flavors, the frosting, the size, and the design. And even if you got all of these things figured out, it would still be hard to say how much it would cost you because it would depend on your cakemaker or baker. Experienced and professional bakers and cakemakers create better-tasting cakes that look a lot more polished, so you can expect their cakes to be pricier than those made by home bakers.