Different Kinds of Money: Middle Aged Men Negotiating Porsches Edition

From Bloomberg's "Whining Harvard Professors Discover Obamacare":

...Milton Friedman famously divided spending into four kinds, which P.J. O'Rourke once summarized as follows:

1. You spend your money on yourself. You're motivated to get the thing you want most at the best price. This is the way middle-aged men haggle with Porsche dealers.

2. You spend your money on other people. You still want a bargain, but you're less interested in pleasing the recipient of your largesse. This is why children get underwear at Christmas.

 3. You spend other people's money on yourself. You get what you want but price no longer matters. The second wives who ride around with the middle-aged men in the Porsches do this kind of spending at Neiman Marcus.

4. You spend other people's money on other people. And in this case, who gives a [damn]?