In life, one has to make concessions and compromises. My wife, for instance, can put up with tons of stress, the apocalypse, etc., but refuses to live without cable TV. It's a small luxury that makes the long hard days at work worth it, and the expense in exchange for piece of mind and relaxation more than justifies the cost.
The Gran Turismo series has been that way for me. I've been playing since the demo for the first one on the PSOne, and have owned every one since. Compared to other forms of entertainment, my GT5 Collector's Edition plus DLC has paid for itself countless times, and will do so until 6 comes out.
Not only that, but the GT series allows me to do at home what can't be done in the real world (without serious consequences)- drink and drive. No need to leave the house when I got a 6 pack (don't drink often so I'm a cheap drunk) and a controller.