In companies, you have Goodwill. It's the difference between the actual value of the company and the market value.
Similarly, the Reventon is priced high and limited to 20 cars to make it unique; hence the price tag. When you are out to buy a car like a high end Lamborghini, Ferrari or a Bugatti, you don't usually care for the price. If you're pouring in a massive amount of cash for car, you probably have a 100 times more cash anyway.
Would I buy it if I had the money? HELL YEAH. It's unique, it's fast and it's got Lamborghini heritage.
Veyron? Yes, it's fast but for me, that's not all. I'd rather own a car from my favorite super car manufacturer and pop my door upwards