The one expensive fish that I completely understand commanding a high price is the crosshatch trigger. Tough to look at that fish and not be impressed.
Some of the others....
95 out of 100 people would probably think a blueface angel ($80) is cooler than a bandit ($1,000), most would think a powder blue ($60) is prettier than a gem ($3,000). In a vacuum, not knowing anything about its rarity, it would probably be 50/50 between a peppermint ($20,000) and a nice flame angel ($45). Like that clarion that was on DD last week - wasn't it $4,000? Imagine seeing that and a red sea regal in the same tank - which would most everyday people choose?
Now would I trade every fish I own for a peppermint, or a gem, or a bandit? OF COURSE!