In addition to the HVAC, spend a little more on good insulation and good windows. They are so boring but make a world of difference in your comfort.

Cabinet inserts that reflect the way you live and cook. Built-in shelving and cabinets.

Radiant floor heat, nicer windows, moving pipes to avoid soffits, putting laundry somewhere convenient, upgraded faucets/shower fixtures, deliberate well designed landscaping, layers of lighting thoughtfully designed and fixtures from higher end companies (you can always tell the plasticy fixtures even from 20 feet away), a couple nicely constructed built-ins, nice door hardware, heavy, nicely made, interior doors (tru-stile), making sure the details make sense and things look finished (for example, not terminating backsplash tile with a raw tile edge on the top, but instead having a shelf, decent looking bullnose, cabinets, etc.

I fell in love with a floor tile that would’ve blown my budget for the main bath, so I used it in the small first floor bathroom where I could more easily absorb the smaller price increase. So happy I did.

Windows

My favorite splurge was for custom
Drawers and shelves for our small walk in pantry. We considered Elfa and basic wire shelving but went with something similar to California closets. It made the small place beautiful and functional and was worth every penny.

Also, like a PP , we ordered an extra shelf for every upper cabinet so that we wouldn’t need after market organizers.