If you are a self-employed businessman, say a traveling salesman, you need a dependable car, and you need presentable clothes. You may have to spend a lot of money on a suitable vehicle and respectable professional attire. It makes sense to borrow money for these items because you need them NOW, you simply cannot save up for them and buy them later. Besides, you can write off on your taxes the business expense, and the interest. If interest rates are low, its a no-brainer. And if you anticipate inflation rates are going to rise in the near future, you will wind up paying your creditors less borrowing power than they loaned you.

But if you get an unexpected windfall, you go to Vegas, or you take the W&K to Disneyland.