but having worked in the business for nearly 30 years, I think there are three areas to control costs:
Simplify the structure - There's a reason why there are a zillion split level entry homes in Utah. They are structurally simple. cut up roofs, multiple dormers, over complicated foundations really suck up your funds before you get to the fun stuff (finishes).
Be smart about your HVAC system - This is a worthy place to spend money. Ask for ROI information if you can get it. You want it too work effectively. Overcomplicating the system doesn't make it better.
Electrical - I don't like to spend a ton on outlets, switches and lights because they can be changed in the future. I don't see anything bad with simple old school switches. Do however make sure your panel is sufficiently sized with space for future circuits. I have a small home with a 120 amp service, plenty of space when I added a Type 2 charger last year.

You asked where to put money - Windows, flooring, cabinets, tops, appliances, plumbing fixtures (Moen or Kohler only).