When my wife was building they did not want to leave that money on the table. They had optional upgrades on things like these fans. When a guy is paying $750k for a house, adding another few hundred for some high tech wizz bang is easy to sell.
I do know what you are saying tho. If they didn't buy the upgrade, they got the cheapest thing that would meet the code.
I saw a few of these low ball houses, usually bought by an "investor" and the difference was striking if you really looked. The problem is people don't really look.
