This frugal philosophy of shopping is classic and okay.

I mean in parts of Asia and elsewhere it's a kind of endless price haggling to the point of wearing down sellers/buyers. It's a process.

In the west it's kind of like the battle of the coupons and small print, turning details into successful retails, and also wearing individuals down at the check out.

When someone is good at both they become olympian shoppers extraordinaire. Then they have to be careful to not make a pattern or habit of leaving a retail location with more money than when they went into that location. Sooner or later they get tagged or get into trouble.

Now about the theory of marriage, I don't know it's too much like a quantum theory of the many worlds problem.