Asked him how much he paid his wife for sex.
Fun as it is to mock MBAs, especially ones with such a sophomoric view of economics, your young MBA was pretty dopey if he couldn't handle that riposte. The obvious answer is surely that he doesn't pay his wife for sex. They are bartering goods of equivalent value (unless she is not a willing participant!)
His mistake, I think, is in using "pay" in this context, and assuming the exchange of money. In context, goods and services are not worth what money someone will pay for them, goods are worth whatever they can be exchanged for. Money, other goods, favours, political influence... And a more, ahem, fluid view of such exchanges of value is not uncommon in sci-fi.
]]>