Nihon Mura would probably not make it onto your list of options if you are at the cathay and looking for a more budget-friendly option. However, they have a newly launched sumiyaki series of donburis which i personally find super worth!
Didn't quite have confidence in the portion size but when it came i was legitly surprised. Portion of rice and meat was just nice for a meal to fill you up, and there was even side salad and onsen tamago.
Food quality wise was also surprisingly good. The chicken was tender and had a nice charcoal grill, smokey fragrance. The fat pearls of white rice were distinct, not too mushy nor dry, and were well flavoured with donburi sauce.
Prices starts from just $5.50 (coming to perhaps $6.50 after gst and svc charges) for their chicken/pork sumiyaki bowl, $6.80 for salmon and $7.80 for the beef. For the indecisive, they also have super value-for-money double protein options too.