https://www.99.co/blog/singapore/99-...-launch-price/
The site was awarded to the developer in June 2015 at S$345.86 million, which translates to S$755 per square foot (psf) per Gross Floor Area (GFA). Construction costs, including architecture design, is about $350 psf for a mass market condominium. Add them up and you get the base cost.
Next, take 30% of the base cost that will cover the other expenses and profits for the developer. This comes up to about $331 psf,
755 psf + 350 psf + 331 psf = 1436 psf
psf ppr + 350 psf + ((psf ppr + 350)x30%)