But this is the same here in Sacramento area. Size will only be a factor if it means WAY more sound equipment, add-ons, etc.
For a std 4hr wedding reception with no "extras," I'm getting my $750 whether there are 5 people sitting around a table drinking, or 200 peeps.
The number of people who might actually be on the other side of my table doesn't change what I do or how I do it, either before or during an event.
So the fee is the same. If they have a smaller crowd, I'm likelier to get the gig anyway all other things being equal because my pricing is pretty much smack-dab in the middle for a professional service provider in my area. So if they're "watching costs" because they ARE having a smaller crowd, etc., my rate will seem pretty attractive to them.