Because a lot of people like myself love the black clowns. And the rarer the pattern the better looking.

Myself bought a domino clownfish. I got him for 150 bucks. But in the past year I have only seen one other hobbyist with one. But I've seen about a million picassos and ordinary percs and ocellaris'. So you get what you pay for if you want beautiful. Original and exotic than order one of these. If you want a reg clown. Go visit big ALS.