Since you have been to Iwa and Yoshitake, I think Kyubey will feel like a step down. I can recommend a few shops in the general vicinity of your hotel that are not too expensive, and not too hard to book (assuming the CY offers concierge service):
- Sushi Keita in Tsukiji is amazing (better than Iwa or Yoshitake IMO), and a very good value. Lunch starts at Y5,000, and dinner is under Y20,000. More info:
https://www.thesushigeek.com/the-sus...-tsukiji-tokyo
- Sushi Ichijo in Higashi Nihonbashi: not too far from Tokyo Station. Same story, cheap at lunch, still quite reasonable at night (under Y20,000 PP) and really delicious. More info:
https://www.thesushigeek.com/the-sus...honbashi-tokyo
- I think Sushi Taichi in Ginza offers a nighttime omakase in the Y15,000 range. Lunch starts at Y5,000. When I consider food, atmosphere, C/P ratio, and ease of booking, Taichi might be my favorite sushiya in Tokyo. More info:
https://www.thesushigeek.com/the-sus...in-ginza-tokyo