Cold Storage is expensive, there are cheaper supermarkets around, eg, Fairprice, Carrefour, Giant and also the wet markets.
BUT it is very expensive to eat healthy in Singapore, meat is very expensive here along with everything else that is healthy. So you will go through the $$$$ when you grocery shop here.
It is much cheaper to eat out at Hawker centres everyday but not very healthy.
Is this suggesting that meat would be one of the healthiest things to eat...

But seriously... ColdStorage has quite a limited selection in several product categories. I've always considered it more suitable for locals who want to act western for one day. Needless to say, it's also run by locals.
Westerners get groceries from something like Carrefour or several Western Gourmet shops you find across the island. The former being rather cheap, the latter often not. Couple of times a month you can stock up non-perishables from FairPrice etc.
As for the hawker centres, they are perfectly ok. I know dozens of locals who eat there every day of their life and they're still alive and well. It does get little bit boring after a while if you're western.
Restaurants here are charging thru the nose, but not necess. because the food would be any healthier. They have to cover the huge rents, renovate every once in a while, but mostly because of greed. There's a big restaurant boom in Singapore right now, and everyone's out there to make a quick buck. And of course, as usual, they think expats would pay just about anything.