I'm guessing you were pretty far out from the center. That price doesn't align with the experiences of people I'm close to who live there, and who I have visited. But they do live in a more central area.
Also, the HDB-style housing is often less expensive, as some are pretty run down and not likely popular with expats, but they are cheaper.
I lived in Singapore for 10 years in both HDB and condo. Close to the cbd and far.
HDB can be run down yes, but most are not. They simply do not have things like gym and pool.
Majority of the expats will get a condo first and then realise they don’t use any of this stuff and later change to HDB.
Condos are often poorly constructed. I lived in a condo that had just been finished about 6 months earlier. In Jurong east called j gateway. It’s one of the worst buildings I’ve ever been in. They put tiles on the floor that are meant for walls, and the floor to the shower is flat so the water pools and don’t run out causing water splotches.
Anyway my point is: Singapore is cheap to live in. If you want to live near the cbd (unsure why cos most expats prefer to socialise around Holland village) then you have to pay for it. If you don’t want to eat locally and instead order grab food or eat at restaurants then yeah it’s expensive. But that doesn’t make Singapore expensive to live in, your chosen life style is expensive.
Also, the HDB-style housing is often less expensive, as some are pretty run down and not likely popular with expats, but they are cheaper.