War and Peace
How we cite our quotes:
From the time that Pierre began life as a family man on a footing entailing heavy expenditure, he had noticed to his surprise that he spent only half as much as before, and that his affairs – which had been in disorder of late, chiefly because of his first wife's debts – had begun to improve.
Life was cheaper because it was circumscribed: that most expensive luxury, the kind of life that can be changed at any moment, was no longer his nor did he wish for it. He felt that his way of life had now been settled once for all till death and that to change it was not in his power, and so that way of life proved economical. (Epilogue.1.12.12-13)
This ties in interestingly with the previous quotation. If the point of romantic love is family, then it makes sense that society is organized in a way that makes family life more economically efficient than bachelorhood. On the other hand, this kind of contradicts our notion that it's expensive to raise a family. Why might a single guy spend more?