Going back to the lovely wedding I attended over a week ago, I realized something. I probably won't need to reserve 3 hours at the ceremony site!
I remember the groom worrying about rain and saying that they only had the site for an hour for the ceremony. (So if they had to delay it due to rain, they could have been short on time.)
Boldt Castle only gives 1 and 1/2 hour slots for weddings. Duke Gardens probably did the same thing with the wedding I attended. They seemed to have no problem setting up, having a nice ceremony, and cleaning up the site on time. And as far as I could tell, they had no problem taking pictures afterward either! (In other words, they could take photos outside of their ceremony slot)
So, I am revising my estimate for the ceremony location fee to $650, 1 and 1/2 hours for 100 people at $6.50 a head.
$650 down, $5K left to go, lol