Mike, i should have been more specific, I am comparing our hobby to hobbies like collecting art, or other items that do not derive their value from their utility. But in general, or at least in practice, what is best is defined by what the majority of people in the hobby state as being best. This usually correlates with what is most expensive/rare.
As it stands the only difference between what makes a coal "best" is how "rare" it is or how much it cost/ resale value(after grow out).
If you tried to financially "value" a coral, you would look at two things. 1st you would look at what future cashflows it might brings and what value you might derive from it upon sale. Purchase price - (proceeds from selling frags + proceeds from selling future colony)/(required rate of return). The second thing you would look at would be the intangible value you gain from it (enjoyment at looking at it, enjoyment at knowing that you have something rare, prestige in acquiring something that most do not have, essentially all of the reasons that someone buys an expensive piece of fine art).
Both the proceeds from selling the frags and the proceeds from selling the future colony are dependent on the market value of the coral, which is simply what people will pay for it. The intangible value is also directly dependent on the price paid for the item, or the rarity of the item (this is especially true for reef junkies, and not so true to beginners). Therefore the only variable that makes a coral valuable or the best, is the price paid for it, and the impact that price has on other peoples ability to buy it. The value of a $2000 coral is the fact that at this price other people will not be able to buy it, therefore making it rare, where in turn holds up the value of the coral at that price. once the coral has been made available to enough other people, the price will drop as supply increases.
so Mike the only thing that makes one coral better than another is how much it is worth, and the only thing that determines its worth is how much people will pay for it, and its scarcity.