You'll never regret spending money on better cabinets (quality and size/height). Getting the kitchen right will save you $$$ later on (or worse.. your wife will want to move again). Changing countertops is cheaper than most people think... You can upgrade countertops for sub $10k... upgrading cabinets gets crazy expensive.

Some builders go super cheap on Interior doors... upgrading to a better look/design is often not that expensive but will make your house look more expensive.

Carpet = Go with the base or maybe just one step up. IMHO go LPV everywhere on the main floor.. and upgrade to a thicker/higher quality product if you can.

The carpet will always have to be replaced in ~5 years. LPV can last decades (plus, Rugs can change as trends change)

Most builders will use the cheapest paint possible... however, painting an entire house later on will cost ~$10-30k. If upgrading the paint is an option... DO IT! 3-tone paint... Flat whiter/brighter ceiling, eggshell (not satin) walls, and trim & doors a slight change from walls. (3-tone paint is the difference between builder-grade and custom home)

Its almost always cheaper to finish a basement with a builder than after... think about it (if its in the budget)

Technology changes... DO NOT spend the money on smart home / built-in speakers. You can do that later yourself for less.

Also.. a 3rd car garage is always the correct answer. Only regret comes from a 2 car garage.