subsale is not necessary cheaper but the good about subsale is that the house is ready and can be use immediately once it is purchase, what you see is what you get and you have also info on the neighborhood and facilities around. Another things is subsale price is negotiable most of the time.

If you buy from developer, there is always a risk that the units may not be completed or is not what you have expected. The neighborhood also is almost non-existent assuming is a totally new project. Besides that you need to wait for 2 to 3 years for the house to be ready. But the good thing is most of the developers will adsorb lawyer fee, and mark up selling price, this and that so you pay a significant lower downpayment