All of this depends upon your investment and the type of house you are looking for. Building on a vacant plot as per your needs will cost you a lot more than buying a pre-built house because there are additional charges to pay for the construction on your plot after purchasing vacant land. Whereas, buying a pre-built home will spare you from paying any additional amount because you will get a pre-built house. However, if you are looking for a customized house that you can not get from any of the pre-built residential communities then buying a vacant plot and construction on it would be the best option for you.