No, the aggregate isn't important: the thought experiment is the same as if everybody earned $251k and spend $1k on rent -- but the percentage of income spend on rent would be radically different. But yes, if everybody suddenly had $250k disposable income, prices would be higher.
I think the point GP is trying to make, is that it matters more if you can afford in absolute dollars to have a family on whatever is left when you're done paying rent, not what the percentage is.
I think the point GP is trying to make, is that it matters more if you can afford in absolute dollars to have a family on whatever is left when you're done paying rent, not what the percentage is.