What enlightened said about living costs in the NY-NJ area is totally correct.
I’ve heard homeowners in Brooklyn say how their Homes are worth $1000000, so you say if you can’t make ends meet why don’t you move out? And they look at you like you just said the most scandalous comment.
Another point is that before your kids enter the shidduch scene explain to the exactly what it means to be in kollel. Tell them how it is, don’t paint a rosy picture, that’s unrealistic.