I think you missed it but they do not offer ala carte anymore. Our upcoming cruise on Ovation is $49.99 pp with this description:
Introducing a prix-fixe, palate pleasing, pre-cruise exclusive at Izumi. Enjoy an exotic Asian-inspired experience and choose from an inventive menu of favorite dishes crafted by Master Sushi Chef Travis Kamiyama. This dining experience is a five-course meal for a fixed price - only available pre-cruise.
Start off with one (1) Miso Soup and one (1) starter, like Shrimp Tempura. Pick your choice of one (1) Signature Roll or a flavorful bowl of Ramen. Enjoy five (5) pieces of your favorite type of Sashimi or Nigiri — and top it all off with one (1) delicious dessert like mochi ice cream offered in a variety of flavors. It’s all made to order with bold flavors, the best ingredients and impeccable presentation. Reserve now, as this prix-fixe menu won’t be available for purchase onboard.