Sam: This Rama is how we’ve paskened for centuries, at least.
$50,000, after-taxes, per-person, is far in excess of “middle class” in NYC. That would be defining middle class for a two parent household as being in the neighborhood of $150,000 pre-tax per year. Completely absurd. And the prenup amount is the same across the US, it isn’t a NYC amount. And it is post-tax dollars not pre-tax dollars. And it is for (mezonos supposedly of) one person not an amount for a family. And the prenup indexes it to inflation, meaning the amount will be more than $150/day, $55,000/year, when it kicks in.
More fundamentally, a husband is not even required to give his wife mezonos in amount equivalent to an upper middle class income lifestyle for her. (And, again, this prenup amount is far far in excess of middle class.) He only obligated to cover mezonos for basic living expenses. And in many cases (and with the Rama in virtually all cases the prenup applies to) he has no chiyuv to give her any mezonos.
Bottom line: The BDA prenup is set to an amount clearly and overtly and unambiguously to be a severe penalty that the vast majority of husbands could not even afford to pay (with the obvious intent of forcing him into giving a Get even in cases where he has no halachic obligation to give a Get). To call it mezonos is an unmitigated joke.
Read Rav Elyashev’s teshuva I cited on the issue of agreeing to a monetary Shibud. Rav Elyashev says that since at the time of signing he expected it to never actually coming into play, he effectively never agreed to it. Rav Elyashev further rules that even if he had properly and bindingly agreed to it, if the result is that it pressures him into giving a Get then it is a Get Me’usa.