What is typical when selling a business with a broker?

I have a friend who recently sold what I would consider a rather large business: 150 employees, property and buildings.
He contracted with broker, for a complicated fee that depended upon the sale price and other factors.

First the broker made an assessment and helped with the staging.
Then they went through a list of ~1000 potential companies that might be interested .
That list was whittled down to about 50 prospects and letters and other info was sent to them.
About 10 made reasonable offers.
The broker selected 3 to bring to my friend.
Then the dealing began. All 3 gave offers my friend would accept but one offered something extra he wanted.
The broker received about 5% for all that work.
My friend was quite happy with the whole process.

^^That was very interesting and very informative.