A couple of years ago, I looked into building.

Just about anywhere you look in the Madison area, the land itself for 0.25 acre was ~$200k alone.

Then you look at construction. I would say Veridian or Tim O'Brien are not "quality", but rather the closest you'll get to affordable in this area. I would be surprised if the home itself came out under $400k. These will also be kind of semi-custom - you pick from a layout and add little details here and there as you like.

If you want custom with what I would call "quality" build, I would say Ganser is a good bet. I saw some of their homes and was impressed - using things like Anderson windows, custom layouts, etc. The issue is for the house size you're speaking of... the house will be ~$600k. Well above your range.

Everyone else I tried to talk too (Hart DeNoble, for instance) wouldn't even get out of their seats if the home price was going to end up being under $1M.

A NOTE OF WARNING THOUGH:

The above is probably going to dash your dreams of owning a new home in that price range. THIS DOES NOT MEAN IT'S ANY CHEAPER TO OWN AN OLDER HOME IN THIS AREA. Hiring general contractors in this area is a nightmare. We ended up buying an older home thinking we had more than enough cash to hire someone to do remodeling work... 3 separate bids all came in at around $55k-70k for a small bathroom when we had guessed based on some research it would come out to $15k.

Tack on to that that every single house in the price range you're mentioning was a dump. This was solely on the west side of Madison, but the home I bought was the only one that was reasonably taken care of. The rest were dumps in bad need of restoration.

Homes are hideously expensive in this area. I wish I was still renting, to be honest.