It is pretty expensive. I might have overestimated the homecooking costs, so I stand corrected that homecooking is not too cheap, but eating out can be relatively expensive unless you are going to be economic. Homecooking more or less stays the same due to consistent costs of the groceries and the utilities, but eating out is a whole different thing.
I found a neat little source here because personally, I might be skewed or have a way different mileage. For the meals? You can get a decent meal for around SGD 5.00, which is around USD 3.64. Maybe USD 5 / meal if you add drinks and the like. There are stalls called "Economic Cuisine/Rice" that basically gets you rice + meat + veg for that cost... sometimes lower.
I forgot to add that the reason eating out can be slightly cheaper in Singapore is because I am talking about the hawker centres / food courts, not the restaurants or diners. So... these food courts are self-serving, as in you will have to go there and collect your own food and the like, so there is no service charge. I think this would explain why eating out can be cheaper if you go to the food courts. Eating in a restaurant will drain your wallet.