Upgrades: Interior doors, Cabinets (Kitchen), paint (3 tone).. maybe higher end LVP (vs carpet or cheap LVP)
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.