what upgrade what it be on the baseboards from what to what

Upgrade from our builder's standard, which I believe is about 3-3.25", to a 6.5" MDF8263. We would likely only do it on the first floor (where we have 10' ceilings).
Thanks for your help!

Baseboards... But I don't care for levers anyway!

Agreed. Higher baseboards are one of those features that most people can't quite put their finger on but make a big impact to the feel of the house. Changing knobs to levers, however will most likely go unnoticed.

If they will go to an 8" baseboard, even better with a 10' ceiling.

I stand corrected-- I just found out the standard base molding is 4.25".

4.25 is still not big enough with a 10' ceiling. Upgrade that now. Changing out knobs after you have lived there a year or two is easier.

Very good points. Thank you! Casing is going to be 3". Will that look ok with the higher base molding? Also, is it "ok" to have the upgrades base molding on the first floor only or would you splurge to get it throughout the home (2nd floor is all 4 bedrooms and laundry room).

If budget allows why not do both? If you change these things down the road, you will be paying twice for labor. Since it is a new build,I would try to do it now if these are things that make a difference to you. The difference may only be a few hundred dollars for an upgrade in materials. The labor will be the same.

I would go with baseboards. You can easily change the knobs by yourself down the road. As for the baseboards, unless you are handy, you would have to pay someone to cut and nail them.

Maybe you could easily change the knobs. Wouldn't happen in my household, lol.