It's funny you brought that up. I was just about to post a thread about a Facebook group called "Single Moms Wildly Overestimating their Market Value 2.0." I guess that I'll just talk about it here.
It's an incredibly mean-spirited group. I thought that it would be humorous, but the so-called humor is very repetitive. It is screenshots of the type of woman looking for marriage that fbj describes. They "overestimate" their value by being demanding about who they want to date and what they expect out of the relationship. About a third of them are memes with some visual version of "and her kid turned out to be black!"
Allah forbid, if I were to end up looking for love again, I'd much rather a woman be up-front about what she wants. If her profile says she's looking for a husband and that ain't you, babe, you just saved a wasted evening and the high cost of restaurant meals. Why look at a single mom's dating profile and be surprised she has kids?
By the same token, fjb, why try to date women and be surprised that they are looking for marriage? Likely they are on a dating site specifically so they can be upfront about looking for permanence without scaring a guy off on the third date. By saying up front before you've even met that this is what she wants, you have your chance to bail before she sleeps with you and then goes through that whole, "where is this going?" routine that I experienced in the 80's.
Honestly fjb, I'd recommend you look into a love doll.