The same things that make a custom build so special, and a one-of-a-kind asset, also make it a luxury item. Your vision has never been realized before and the budget is up to you to decide. The lot may not have the proper infrastructure, or needs connections run from the road. There are many unforeseen costs that can be involved. Custom homebuyers should anticipate a minimum cost of $400,000, including taxes, site development, property plans, and other expenses.