When I look at a fish and it's price I never (rarely) take into consideration it's looks. The things I think about most are, where did it come from, it's size (freight), and availability. If you're seeing the same $1000 fish week, in week out then maybe they shouldn't be that much unless it's a giant, but if it's something you don't see for sale very often then availability can have an effect on price.
Of course this is not always true for the price. One example off the top of my head would be a Lineatus and Scotts wrasse. While I'm not 100% sure they come from the same area, they are both of similar size and Australian, but the Lineatus generally costs more, despite being somewhat more readily available. It's possible to discount some of this since Scotts are available from other locations much cheaper, but the Australian ones are certainly more colourful.
When I see an Angelfish for $1000+ I can generally see why it costs that much even if I personally would not spend it.
Of course this is not always true for the price. One example off the top of my head would be a Lineatus and Scotts wrasse. While I'm not 100% sure they come from the same area, they are both of similar size and Australian, but the Lineatus generally costs more, despite being somewhat more readily available. It's possible to discount some of this since Scotts are available from other locations much cheaper, but the Australian ones are certainly more colourful.
When I see an Angelfish for $1000+ I can generally see why it costs that much even if I personally would not spend it.