It is quite natural to spend a lot of energy and time designing your dream custom home. You would want your new home to be perfect. Of course, you need to consider other factors such as location, cost and the market trend while building the new home. If you have a wish list which you like to incorporate into your new home, you need to convey the list accurately to your architect and the custom home builder.
If your project is on a sensitive time schedule, then you need to discuss that with the builder and figure out the possibilities. To be honest, custom home building is time consuming. If you want your new home to be built without any compromises, then you need to give it adequate time.
It is a bad idea to buy an existing luxury home. It is well worth your time to hire a builder and build a brand new custom luxury home instead of buying an already built home. If time is a factor, then you are better off going for a normal production home instead of a luxury home.