Calm down, calm down.
I do see your point about getting upset because she wants money for the dog. But, there is one point you need to look at, as I am sure this is one reason rescues charge (although I've never asked ). There are many people who want a dog that cannot afford one. My niece is a great example, although I don't claim her.
Anyway, her jerk of a husband got a free dog from a newspaper, because it was FREE and they didn't have to pay for it. Well, the friggin idiot didn't think of the shots, vet care, food, etc. in the months to come. I ended up paying for shots for that dog and buying it food. I begged her to rehome this dog, but she wouldn't do it. I have no idea where this pup wound up, as I haven't spoken to her for other reasons in 8 months. At least when you ask for money for a dog, people have to think about it instead of jumping in. If you have to pay $250 for a dog, you might think about whether or not you can afford it. I am hoping this little girl is spayed so as not to be used for breeding, so I am going to assume she is. If not, I would INSIST on it and make the vet who does it call you and verify it. Make him sign an agreement saying he will have her spayed and if not, you will take the dog back. Anyway, assuming she is, this guy is paying $250 for a boxer for a pet. You know he has thought about the money since he is paying it, and has a better chance of affording the dog than some lowlife like my niece's husband who just see FREE in an add and jumps in. Just one take on the money thing.
Mom to Buster, 3 yr old brindle and Olive, 2 yr. old reverse brindle
Sweet Roxy, waiting at the bridge, April 10, 2000-April 10, 2009