A lot of it comes down to a mix of snobbishness, sunk cost fallacy, and tribalism.

You can't admit that your $5,000 pair of headphones sound exactly the same as a $300 pair, because:

• You'd no longer be able to pretend that you're better than the people who have $300 headphones.

• You'd have to admit to yourself that you completely wasted $4,700.

• You'd have to realize that the tight-knit community you've formed with other $10k headphone people isn't really bettor or even really distinct from communities of people with $300 headphones.