People looking to build a home for the first time usually ask "How much does it cost to build a new home" or "How much does it cost per square foot to build a new home".
The best answer to this question is, it depends. Just like purchasing a new car, you can spend as much or as little as you want. It's all about what you put on and in the home that drives the price of it.
The hard costs of your new home (foundation, lumber, roof, framing, etc.) are primarily dictated by the house plan. A steep lot can significantly increase the cost of your foundation, already one of the largest costs for your new home. Designing a floor plan that is more compact than spread out or sprawling will save money on the foundation, lumber, framing, roof, sheetrock, and more. Taller, more elaborate ceilings inside the home can significantly add to the price depending on their complexity. Straight run stairs are always less expensive than double-back or U-shaped stairs. Plumbing runs that can be shared (bathrooms back to back, etc.) can save money as well. There are many other structural types of costs that will affect your bottom line that your builder can explain to you as you are designing your new home.
The finishing touches of your home (called "allowances"), and their associated costs, are completely in your control. Things like cabinets, appliances, lighting fixtures, plumbing fixtures, flooring choices, countertops, hardware (doors and cabinets), specialty wiring (entertainment, home automation), garage doors, and landscaping/irrigation can significantly affect your bottom line. How you spend this money is entirely up to you.
At the end of the day, you can spend as much as you want on your new home. Working with a knowledgeable and reputable builder from the very beginning of your project will ensure that you spend what you want and no more.