To me, the beauty of Zebrasoma rostratum is in its lack of color... it is one of the very few truly JET black reef fish... and the LONG nose its developed in relation to the other six species of Zebrasoma is interesting too... but debating beauty is near useless in these forums... I love Zebrasoma species and I own two Z. rostratum and one Z. rostratum/scopas hybrid... with so little adult spawning options, and less and less each year, the Z. rostratum breeds into the scopas population (my theory at least)...
In reference to the market value of this fish... this cannot be discussed without mentioning the chain of custody of this species... Kiritimati (Pacific Ocean Christmas Island) is about 1300 miles straight south of Hawaii, and ALL exports from there, and thus all exports of Zebrasoma rostratum, go through Hawaiian wholesalers... while Z. rostratum has a pretty large range, that is the only place it is exported from to the hobby. Once the Hawaiian wholesalers have them, they are either shipped direct to a LFS, or to a mainland wholesaler (usually of course in LA). The difference in pricing on this fish is so great partly because of this... by going through a wholesaler it will add on another chink in the chain of custody... and thus add on to the price...
Another reason the price varies is that this was never a common fish at Christmas as Luiz said... throughout its range it is never found in densities like the yellow tangs on the Kona Coast of the Big Island of Hawaii... Fishing pressure has diminished these numbers even more at Christmas, despite Christmas being the largest coral atoll in the world (land mass at least). It is NOT the remoteness of Christmas that results in the high prices of black tangs... flame angels are flown out of Christmas by the thousands to Hawaii for cheap... but for every few HUNDRED flame angels, the buyers in Hawaii can expect one black tang... the exporters of Christmas know too they have the market locked on black tangs with no competition... so, with that in mind... knowing the demand is MUCH greater than the supply, price varies greatly on this fish... and a wholesaler can charge a premium for a black tang knowing that... and eventually the retailer for that matter... oh, and if you think they're expensive in the states, the last time I saw a European wholesaler stocklist, they were more expensive than gem tangs!
One other thing to keep in mind is that this fish has an interesting and rather unique pricing structure... the rarest size by far for this species in the market is MEDIUM... the most common size fish are the DINNER PLATE sized adults, and the first year drop tiny juvies, so a medium fish should be worth more in my opinion... and an adapted medium fish that much more, even though this is not as important as with other species as Zebrasoma species are relatively easy to adapt to captivity...
How long have you had this fish? If truly two inches it cannot be that long...
Copps