No federal estate tax on $10m of farm land (kicks in around $13m this year, from what I can tell—the so-called "death tax" is often framed as applying to a whole lot more people than it actually does). Further, I'm pretty sure there are ways to structure a business that'll prevent even amounts exceeding $13m from being affected—granted, that would require advance planning which may or may not have been done.

The rest would vary state by state and depend on the relation to the deceased, but I'm pretty sure it'd be $0 or negligible in most cases, on a $10m estate, for spouse or children at least, even with minimal advance preparation.