I don't think that Pinnacle project in particular is one to use against "over time their value has increased faster than an average dwelling in the vicinity, making them more exclusive and restricting access to those higher and higher up the socio-economic ladder".
It's not gated but it definitely is not affordable now. The first owners probably felt like they won the lottery.
I don't think its value 'has increased faster than an average dwelling in the vicinity': the Pinnacle is very close to the city centre. I live in a shop house around the corner. These are even more expensive. And so are the condos nearby, too.
But in any case, I brought up the Pinnacle as a short-hand for a nice looking HDB, not to say that it's affordable. The city centre is very much not affordable.
You are right that further out, you can get much cheaper flats. Like in almost any city on the planet.
Agreed, stuff like Punggol town is IMO much more accessible and interesting. It's truly an awesome place, affordable, well connected with transit as part of its design, etc.
It's not gated but it definitely is not affordable now. The first owners probably felt like they won the lottery.