You're not talking about snacks, you're talking about dinner Lamian Noodles, oolong noodles 1000 yen can be eaten very well in a bowl, usually 5600 yen. Sushi is cheap and expensive. A box bought in a general supermarket is only a few hundred, about 1000 yen. If you eat in a revolving sushi restaurant, it costs more than 100 yen (1~2 yuan). Of course, there are some expensive ones in it, and the prices are generally differentiated according to the color of the dishes. I suggest you ask before eating. Tempura and other supermarkets also have it, a few hundred yen a box. If you go to the store, it is expensive and cheap.

Generally speaking, the standard of 5000 yen (about 250 RMB) per person per day is basically enough. Of course, if you eat high-end goods like snowflake beef every day, it is another matter.