I often take my gf to fine dining Japanese restaurants in central London, usually the bill ends up over £200 for the 2 of us after service charge but not including wine. ROKA's tasting menus are pretty worth it, but that's about it. The others that I've been to, for example Aqua Kyoto was very fancy and expensive but the food was nowhere near as good. (It's almost always Japanese that we go to, seemingly). Now, in terms of food, if I'm being honest, I've been to £30-£40 Japanese Restaurants in both Bristol and London that offer better. However, I suppose the fancy restaurants give the atmosphere and feel, or the 'experience' as they say, that you wouldn't get in a restaurant 5x cheaper. So I'd only go to these places on occasions such as valentines, birthdays, etc. As for me, they're not worth it.