"Knowing if the potential buyer who gave an offer is a large company and how much they make can help you get a sense of what you could reasonably counter with."
You made good points, but not this one.
Shouldn't matter if it's a large company and how much they make.
The domains value should stand on it's own.
Try to imagine the price of everything you buy is determined by who you are and how much you make.
This is exactly why buyers hide their identity.
Knowing the buyer helps to know how to negotiate but shouldn't have any influence on the amount.
I think it's better to be ready with several bullet points as to why seller has set the price.
Agree with Paul,
"Have a good product and you can set your price. Domaining is about buying at the right price -- not selling at the right price IMO"
If your dumping domains after 1 year let us know so we can get ahead of those darn drop catchers
Keep in mind most large dollar sales have had a hold period average 7-10+ years. That's one thing I consider when I buy. Based on the market today could I sell for 10x 10 years reg ? If it's a yes then It's worth the hold.
Happy Hunting !