if you want to have a good meal, try to go to expensive restaurants during lunchtime.
they usually have good discounted sets for lunch, which cost more durng dinnertime.
for dinner, can settle for ramen or kaiten sushi (approx. $10-12)
(dont believe me, just compare the prices of reputable japanese restaurants in singapore - lunch menu price and dinner menu price. almost the same food, more ex for dinner. same principle)