I think it has more to do with pride of ownership & bragging rights than anything else.
For example, does the $3,800 Denon DVD-5910 player sound better than a $800 Denon (or other brands) or even a $300 Denon? And how much better does the picture actually look in everyday application to justify the ridiculous price tag?
Insignificant differences.
Pure bragging rights.
Of course, if you can afford it, there is nothing wrong with that. Who would mind owning one?