Think about it, when you're dirt poor you'll do anything to get out of it. As a woman what better way to get out than to find a man with more money. She'll instantly find any guy with more money to be attractive. Men don't care about a womans social class. If she's hot that's all that matters .

Sure maybe if a guy is simply wealthier she still might think he's more attractive but if she already has comfort and stability it won't matter as much. She isn't gonna risk such a thing unless the relationship is going sour.

On top of that a man can have all the money in the world but if she feels no connection to him his money is useless. Unless she's a gold digger a woman won't leave her man just because some other guy has a little bit more in his bank account. You wouldn't want a woman like that anyways.