Building an Asset in Instalments - When you buy an asset directly from the builder/developer, you are building the property over a period of time, therefore you can enjoy paying over a longer period of time to leverage your funds to a property ownership with ease. Apart from the ease of ownership by paying in easy instalments over longer periods of time, there is of course the advantage of moving into a new home that has never been lived in.
When you compare this with acquiring an asset that is ready to move, you would definitely enjoy early possession and be more sure about the property deliverables that you would get, but more often than not, you may end up being in a property that has been lived in and may be older property. While the older properties may offer the readiness, but may lack the new feel and the new enhancements that most of the property developers would offer to be competitive in the market place.
In a lot of cases, the developers may be offering lucrative offers like 30% upfront and balance on possession or many other permutations and combinations like these to make it easier for you to own a property.
Another interesting factor is that if you choose to acquire the property with a mortgage partner in place, then you EMIs will gradually grow over a period of time instead of the entire EMI coming head on.