Yeah; they can be pricey and really need a large predator tank.
My favorites:
•Zebra shark,
•Leopard shark -both too big for aquariums
•Dwarf Lantern shark -Only a few inches long and flourescent, but requires high pressure and cold water
•Chainlink Dogfish shark -also fluoresces, requires cold water
This narrows my list down to:
•Coral catshark,
•Bamboo shark,
•Epaulette Shark, or
•Short tail nurse shark....
However, still:
•they are often jumpers (with a fish that big, you want to secure your lid with bricks),
•they’re very dirty (need much bigger skimmer, and frequent WCs),
•They often destroy corals, knocking things over constantly, as they burrow through the reefs and rockwork (so no stacked rocks; every rock is in the sandbed)
•and of course, they can potentially eat any fish, inverts, clams (so limited inverts, and no bite-size fish).
For every issue, there is a solution. But for me, Its not worth it to get one at this time. But they sure are beautiful and amazing fish though! And they will always be my favorite!