It's been awhile since I've seen as sly a leftist attack on free markets and liberty as this one. I doubt the author really means it that explicitly, but I calls 'em as I sees 'em, and ridiculing hyper-expensive one-offs as bourgeois excess has been a staple of the left for more than a century.
Let's put it another way. Far from showcasing things "you shouldn't buy," I think this site shows just how industrious entrepreneurs can be in their efforts to separate the rich from their money. When I see things like this I don't view it from the consumer's perspective, a place I'm not likely to ever see, but instead from the producer's, which is a place I most definitely could be, some day. The reason most such things are expensive is because it takes a lot of talented people a long time to produce them, and each time someone very very rich buys one they become less rich while everyone involved in their production becomes more wealthy.
It's also important to understand that the producers of such amazingly expensive baubles live an extremely precarious life. The audience for such items can be counted in the low dozens, world-wide, and what appeals to, say, a hip-hop artist looking to cash their first royalty check today may not appeal to them tomorrow. It may be very glamorous to cater to such people, but it's not very smart.
In a market economy with a thriving middle class, the smart producer seeks to maximize the appeal of his or her product by making it affordable to as many people as possible. People like you and me. There are just so many more of us. An entrepreneur who caters to the Paris Hiltons of the world will never ever be richer than one who caters to the Joe and Jane Sixpacks of it. And so they do, and so we are the ones who benefit.
The hyper-rich have had their needs met since the beginning of time, and they always will. Attempts to "rectify" this "injustice" only serve to make the rich more clever about how they hide their money, and unlike you and me the rich can hire smart people to do this for them. The end result only makes it harder for smart entrepreneurs to reach the rest of us.