Why do humans buy ridiculous and outrageously expensive things? It's a form of ancient signaling called "peacocking". We do it for 2 main reasons. We do it to attract mates and we do it to show dominance over others.
Peacocking as it sounds come from the peacock who tries to make himself bigger and badder than he actually is. Those tail feathers are used to scare off rivals and to attract mates. In Texas they call this having all hat and no cattle.
Humans do this all the time in the form of giant trucks, sports cars, $4,000 Armani suits, gold jewelry, trophy wives, 15,000 sq/ft mansions for 2 people, a 737 jet with TRUMP on the side of it, etc. etc. etc.
This type of stupidity like over eating and not saving for retirement should go to the waste side like many of our other animalistic traits. Are you an animal or a modern man? Can you control your desires or do you react to them on a whim?
Note: this is incredibly stupid if you're already married. Nothing like advertising to the world that you have a little dick when you're married and also drive a Ferrari.