Luxury house plans are very tempting - who has not dreamed of a palatial home as seen in movies and wealthy neighborhoods. A lot of factors make luxury homes more expensive, such as their large square footage, swimming pools, large porches, large plots of land, etc. One factor that is easily overlooked in the initial considerations for a new luxury house is the cost of interior design and finishes.
It's hard to imagine it just from the house plan itself, but a large portion of the total cost to build a luxury home goes into finishes and details. Features ranging from the basics such as materials for flooring or walls all the way to appliances, kitchen counters, a fireplace, etc. can add a lot of money to your total costs.
When you are thinking about going with a luxury house plan, keep in mind that you should take a good look at whether you can afford what the plan and sample drawings or pictures seem to promise. Ultimately, if your finishes cannot keep up, your new home will not feel as luxurious as you might have hoped.A way to get around financial constraints and perhaps even have your cake and eat it too is to be smart about which features and details to add immediately and which ones to add on later. Some things can be added or replaced much more easily than others at a later point in time. Some appliances for example can easily be swapped, especially if they come in standard sizes or are not too tightly integrated (e.g. a free-standing fridge is easy to replace). You can also put basics in place, such as plumbing, wiring or chimneys to be "feature-ready", so that you can add a Jacuzzi, fireplace, or home theater later with ease, and in the meantime use the space in a way that does not give away the fact that you still have bigger plans for it.
On the opposite end, some things are messy, expensive, and painful to change once they are in place, such as plumbing, wiring, flooring, walls, ceilings, windows, kitchen cabinets, etc. Try to get these things right from the start, to save money and to avoid living in a construction site long after your home is supposed to be finished.
So, before you buy you luxury house plans, keep in mind that the devil (and dollar) really is in the details. Make sure to think through your final vision of how you want to live and how much money will have to go into the interior. Ultimately, the interior is what you will experience every day, and finishes and details really make or break a luxury home.