I got married in the dark. Seriously. My wife's birthday is New Year's Eve, and we loved Marietta Square (as did Gen Sherman back in the day). No events in the day without a special permit. So a 6pm wedding on New Year's Eve is going to be dark. Didn't bother with professional phots, just our friends. We've got hundreds of photos of our wedding, and they're that bit more special because they're from our friends. It meant a lot more to us than a sunshine wedding for several grand when everyone could fit us in.
Funny bit - we had a judge marry us. She charged a few hundred to do the biz, so I made sure the money was in cash in a big brown envelope and people were primed to take photos of me handing over a brown envelope full of cash to a judge in her robes.
Charge by the pound then the fatter have to pay more also if they want to cheap out they can always cut parts off the dog/wife/children and bring the cost down. You also have the option of peeling the dog and inflating the remaining skin with helium.
In the early days of the business (OHS) i charged $850 for an 8 hour day. $1200 became an industry norm in the noughties and over time i moved up to $1600 for a six hour. Some consultants charge less and we do miss the odd bid based on price, but the business makes enough to get by.
I guess my point is, charge whatever the market will pay.